PHP日期时间处理完全指南：从基础到高级应用

日期时间处理是Web开发中的常见需求，从简单的时间戳到复杂的时区转换，PHP提供了丰富的日期时间处理功能。本文将分享一些实用的日期时间处理技巧和最佳实践。

基础日期时间操作

1. 基本函数和类

<?php
// 基础日期时间操作
echo "=== 基础日期时间操作 ===\n";

// 获取当前时间戳
$timestamp = time();
echo "当前时间戳: $timestamp\n";

// 格式化时间戳
echo "格式化时间: " . date('Y-m-d H:i:s', $timestamp) . "\n";
echo "中文格式: " . date('Y年m月d日 H:i:s', $timestamp) . "\n";

// 常用日期格式
$formats = [
    'Y-m-d' => '年-月-日',
    'Y-m-d H:i:s' => '年-月-日 时:分:秒',
    'Y/m/d' => '年/月/日',
    'M d, Y' => '英文月 日, 年',
    'l, F j, Y' => '星期, 月份 日, 年',
    'c' => 'ISO 8601格式',
    'r' => 'RFC 2822格式'
];

echo "\n常用日期格式:\n";
foreach ($formats as $format => $description) {
    echo "$description ($format): " . date($format) . "\n";
}

// 解析日期字符串
$dateString = '2023-08-05 15:30:45';
$parsedTimestamp = strtotime($dateString);
echo "\n解析日期字符串 '$dateString': $parsedTimestamp\n";
echo "转换回格式: " . date('Y-m-d H:i:s', $parsedTimestamp) . "\n";

// 相对时间解析
$relativeFormats = [
    'now',
    '+1 day',
    '-1 week',
    '+2 months',
    'next Monday',
    'last Friday',
    'first day of this month',
    'last day of next month'
];

echo "\n相对时间解析:\n";
foreach ($relativeFormats as $format) {
    $timestamp = strtotime($format);
    echo "$format: " . date('Y-m-d H:i:s', $timestamp) . "\n";
}

// 日期时间工具类
class DateTimeHelper {
    
    // 格式化时间差
    public static function formatTimeDiff($timestamp1, $timestamp2 = null) {
        $timestamp2 = $timestamp2 ?: time();
        $diff = abs($timestamp2 - $timestamp1);
        
        $units = [
            '年' => 365 * 24 * 3600,
            '月' => 30 * 24 * 3600,
            '周' => 7 * 24 * 3600,
            '天' => 24 * 3600,
            '小时' => 3600,
            '分钟' => 60,
            '秒' => 1
        ];
        
        foreach ($units as $unit => $seconds) {
            if ($diff >= $seconds) {
                $count = floor($diff / $seconds);
                return $count . $unit . '前';
            }
        }
        
        return '刚刚';
    }
    
    // 判断是否为工作日
    public static function isWorkday($timestamp = null) {
        $timestamp = $timestamp ?: time();
        $dayOfWeek = date('N', $timestamp); // 1-7, 1为周一
        return $dayOfWeek >= 1 && $dayOfWeek <= 5;
    }
    
    // 获取月份天数
    public static function getDaysInMonth($year, $month) {
        return date('t', mktime(0, 0, 0, $month, 1, $year));
    }
    
    // 获取季度
    public static function getQuarter($timestamp = null) {
        $timestamp = $timestamp ?: time();
        $month = date('n', $timestamp);
        return ceil($month / 3);
    }
    
    // 获取星座
    public static function getZodiacSign($month, $day) {
        $signs = [
            ['摩羯座', 1, 20], ['水瓶座', 2, 19], ['双鱼座', 3, 21],
            ['白羊座', 4, 20], ['金牛座', 5, 21], ['双子座', 6, 22],
            ['巨蟹座', 7, 23], ['狮子座', 8, 23], ['处女座', 9, 23],
            ['天秤座', 10, 24], ['天蝎座', 11, 23], ['射手座', 12, 22]
        ];
        
        foreach ($signs as $i => $sign) {
            if (($month == $sign[1] && $day >= $sign[2]) || 
                ($month == ($sign[1] % 12) + 1 && $day < $signs[($i + 1) % 12][2])) {
                return $sign[0];
            }
        }
        
        return '摩羯座';
    }
    
    // 计算年龄
    public static function calculateAge($birthDate, $currentDate = null) {
        $currentDate = $currentDate ?: date('Y-m-d');
        
        $birth = new DateTime($birthDate);
        $current = new DateTime($currentDate);
        
        return $birth->diff($current)->y;
    }
}

// 使用日期时间工具类
echo "\n=== 日期时间工具类示例 ===\n";

// 时间差格式化
$pastTime = strtotime('-2 hours -30 minutes');
echo "时间差: " . DateTimeHelper::formatTimeDiff($pastTime) . "\n";

// 工作日判断
echo "今天是工作日: " . (DateTimeHelper::isWorkday() ? '是' : '否') . "\n";

// 月份天数
echo "2023年2月天数: " . DateTimeHelper::getDaysInMonth(2023, 2) . "\n";
echo "2024年2月天数: " . DateTimeHelper::getDaysInMonth(2024, 2) . "\n";

// 季度
echo "当前季度: 第" . DateTimeHelper::getQuarter() . "季度\n";

// 星座
echo "8月5日星座: " . DateTimeHelper::getZodiacSign(8, 5) . "\n";

// 年龄计算
echo "1990-05-15出生年龄: " . DateTimeHelper::calculateAge('1990-05-15') . "岁\n";
?>

2. DateTime类的使用

<?php
// DateTime类详细使用
echo "=== DateTime类使用 ===\n";

// 创建DateTime对象
$now = new DateTime();
echo "当前时间: " . $now->format('Y-m-d H:i:s') . "\n";

// 从字符串创建
$specificDate = new DateTime('2023-08-05 15:30:45');
echo "指定时间: " . $specificDate->format('Y-m-d H:i:s') . "\n";

// 从格式创建
$customFormat = DateTime::createFromFormat('d/m/Y H:i', '05/08/2023 15:30');
echo "自定义格式: " . $customFormat->format('Y-m-d H:i:s') . "\n";

// 时间修改
$modifiedDate = clone $now;
$modifiedDate->add(new DateInterval('P1Y2M3DT4H5M6S')); // 1年2月3天4小时5分6秒
echo "增加时间后: " . $modifiedDate->format('Y-m-d H:i:s') . "\n";

$modifiedDate->sub(new DateInterval('P6M')); // 减去6个月
echo "减去6个月后: " . $modifiedDate->format('Y-m-d H:i:s') . "\n";

// 设置特定日期
$setDate = clone $now;
$setDate->setDate(2023, 12, 25);
$setDate->setTime(18, 30, 0);
echo "设置圣诞节: " . $setDate->format('Y-m-d H:i:s') . "\n";

// DateTime工具类
class DateTimeManager {
    private $dateTime;
    
    public function __construct($dateTime = null) {
        if ($dateTime instanceof DateTime) {
            $this->dateTime = clone $dateTime;
        } elseif (is_string($dateTime)) {
            $this->dateTime = new DateTime($dateTime);
        } else {
            $this->dateTime = new DateTime();
        }
    }
    
    // 链式操作
    public function addYears($years) {
        $this->dateTime->add(new DateInterval("P{$years}Y"));
        return $this;
    }
    
    public function addMonths($months) {
        $this->dateTime->add(new DateInterval("P{$months}M"));
        return $this;
    }
    
    public function addDays($days) {
        $this->dateTime->add(new DateInterval("P{$days}D"));
        return $this;
    }
    
    public function addHours($hours) {
        $this->dateTime->add(new DateInterval("PT{$hours}H"));
        return $this;
    }
    
    public function subYears($years) {
        $this->dateTime->sub(new DateInterval("P{$years}Y"));
        return $this;
    }
    
    public function subMonths($months) {
        $this->dateTime->sub(new DateInterval("P{$months}M"));
        return $this;
    }
    
    public function subDays($days) {
        $this->dateTime->sub(new DateInterval("P{$days}D"));
        return $this;
    }
    
    // 获取月初
    public function startOfMonth() {
        $this->dateTime->setDate(
            $this->dateTime->format('Y'),
            $this->dateTime->format('n'),
            1
        )->setTime(0, 0, 0);
        return $this;
    }
    
    // 获取月末
    public function endOfMonth() {
        $this->dateTime->setDate(
            $this->dateTime->format('Y'),
            $this->dateTime->format('n'),
            $this->dateTime->format('t')
        )->setTime(23, 59, 59);
        return $this;
    }
    
    // 获取周一
    public function startOfWeek() {
        $dayOfWeek = $this->dateTime->format('N');
        if ($dayOfWeek != 1) {
            $this->dateTime->sub(new DateInterval('P' . ($dayOfWeek - 1) . 'D'));
        }
        $this->dateTime->setTime(0, 0, 0);
        return $this;
    }
    
    // 获取周日
    public function endOfWeek() {
        $dayOfWeek = $this->dateTime->format('N');
        if ($dayOfWeek != 7) {
            $this->dateTime->add(new DateInterval('P' . (7 - $dayOfWeek) . 'D'));
        }
        $this->dateTime->setTime(23, 59, 59);
        return $this;
    }
    
    // 判断是否为今天
    public function isToday() {
        $today = new DateTime();
        return $this->dateTime->format('Y-m-d') === $today->format('Y-m-d');
    }
    
    // 判断是否为昨天
    public function isYesterday() {
        $yesterday = new DateTime('-1 day');
        return $this->dateTime->format('Y-m-d') === $yesterday->format('Y-m-d');
    }
    
    // 判断是否为明天
    public function isTomorrow() {
        $tomorrow = new DateTime('+1 day');
        return $this->dateTime->format('Y-m-d') === $tomorrow->format('Y-m-d');
    }
    
    // 判断是否为周末
    public function isWeekend() {
        $dayOfWeek = $this->dateTime->format('N');
        return $dayOfWeek >= 6;
    }
    
    // 获取友好时间格式
    public function toFriendlyString() {
        $now = new DateTime();
        $diff = $now->getTimestamp() - $this->dateTime->getTimestamp();
        
        if ($diff < 60) {
            return '刚刚';
        } elseif ($diff < 3600) {
            return floor($diff / 60) . '分钟前';
        } elseif ($diff < 86400) {
            return floor($diff / 3600) . '小时前';
        } elseif ($diff < 604800) {
            return floor($diff / 86400) . '天前';
        } else {
            return $this->dateTime->format('Y-m-d');
        }
    }
    
    // 格式化输出
    public function format($format = 'Y-m-d H:i:s') {
        return $this->dateTime->format($format);
    }
    
    // 获取DateTime对象
    public function getDateTime() {
        return clone $this->dateTime;
    }
    
    // 比较日期
    public function isBefore(DateTime $date) {
        return $this->dateTime < $date;
    }
    
    public function isAfter(DateTime $date) {
        return $this->dateTime > $date;
    }
    
    public function equals(DateTime $date) {
        return $this->dateTime == $date;
    }
}

// 使用DateTime管理器
echo "\n=== DateTime管理器示例 ===\n";

$dtm = new DateTimeManager();
echo "当前时间: " . $dtm->format() . "\n";

// 链式操作
$future = new DateTimeManager();
$future->addYears(1)->addMonths(2)->addDays(15);
echo "1年2月15天后: " . $future->format() . "\n";

// 月初月末
$monthStart = new DateTimeManager();
$monthStart->startOfMonth();
echo "本月开始: " . $monthStart->format() . "\n";

$monthEnd = new DateTimeManager();
$monthEnd->endOfMonth();
echo "本月结束: " . $monthEnd->format() . "\n";

// 周开始结束
$weekStart = new DateTimeManager();
$weekStart->startOfWeek();
echo "本周开始: " . $weekStart->format() . "\n";

$weekEnd = new DateTimeManager();
$weekEnd->endOfWeek();
echo "本周结束: " . $weekEnd->format() . "\n";

// 判断方法
$testDate = new DateTimeManager();
echo "是否为今天: " . ($testDate->isToday() ? '是' : '否') . "\n";
echo "是否为周末: " . ($testDate->isWeekend() ? '是' : '否') . "\n";

// 友好时间
$pastTime = new DateTimeManager('-2 hours');
echo "友好时间: " . $pastTime->toFriendlyString() . "\n";
?>

3. 时区处理

<?php
// 时区处理
echo "=== 时区处理 ===\n";

// 获取默认时区
echo "默认时区: " . date_default_timezone_get() . "\n";

// 设置时区
date_default_timezone_set('Asia/Shanghai');
echo "设置后时区: " . date_default_timezone_get() . "\n";

// 不同时区的时间
$timezones = [
    'Asia/Shanghai' => '上海',
    'America/New_York' => '纽约',
    'Europe/London' => '伦敦',
    'Asia/Tokyo' => '东京',
    'Australia/Sydney' => '悉尼'
];

echo "\n不同时区当前时间:\n";
foreach ($timezones as $timezone => $city) {
    $dt = new DateTime('now', new DateTimeZone($timezone));
    echo "$city ($timezone): " . $dt->format('Y-m-d H:i:s T') . "\n";
}

// 时区转换类
class TimezoneConverter {
    
    // 转换时区
    public static function convert($dateTime, $fromTimezone, $toTimezone) {
        if (is_string($dateTime)) {
            $dt = new DateTime($dateTime, new DateTimeZone($fromTimezone));
        } else {
            $dt = clone $dateTime;
            $dt->setTimezone(new DateTimeZone($fromTimezone));
        }
        
        $dt->setTimezone(new DateTimeZone($toTimezone));
        return $dt;
    }
    
    // 获取时区偏移
    public static function getTimezoneOffset($timezone, $datetime = null) {
        $datetime = $datetime ?: new DateTime();
        $tz = new DateTimeZone($timezone);
        return $tz->getOffset($datetime);
    }
    
    // 获取时区列表
    public static function getTimezoneList($region = null) {
        $timezones = DateTimeZone::listIdentifiers();
        
        if ($region) {
            $regionConstant = constant('DateTimeZone::' . strtoupper($region));
            $timezones = DateTimeZone::listIdentifiers($regionConstant);
        }
        
        return $timezones;
    }
    
    // 格式化时区偏移
    public static function formatOffset($offset) {
        $hours = intval($offset / 3600);
        $minutes = abs(($offset % 3600) / 60);
        
        return sprintf('%+03d:%02d', $hours, $minutes);
    }
    
    // 获取时区信息
    public static function getTimezoneInfo($timezone) {
        $tz = new DateTimeZone($timezone);
        $now = new DateTime('now', $tz);
        
        return [
            'timezone' => $timezone,
            'offset' => $tz->getOffset($now),
            'offset_formatted' => self::formatOffset($tz->getOffset($now)),
            'current_time' => $now->format('Y-m-d H:i:s T'),
            'is_dst' => $now->format('I') == '1'
        ];
    }
    
    // 批量转换时区
    public static function convertMultiple($dateTime, $fromTimezone, $toTimezones) {
        $results = [];
        
        foreach ($toTimezones as $timezone) {
            $converted = self::convert($dateTime, $fromTimezone, $timezone);
            $results[$timezone] = $converted->format('Y-m-d H:i:s T');
        }
        
        return $results;
    }
}

// 使用时区转换器
echo "\n=== 时区转换器示例 ===\n";

// 时区转换
$shanghaiTime = '2023-08-05 15:30:00';
$newYorkTime = TimezoneConverter::convert($shanghaiTime, 'Asia/Shanghai', 'America/New_York');
echo "上海时间 $shanghaiTime 转换为纽约时间: " . $newYorkTime->format('Y-m-d H:i:s T') . "\n";

// 获取时区偏移
$offset = TimezoneConverter::getTimezoneOffset('Asia/Shanghai');
echo "上海时区偏移: " . TimezoneConverter::formatOffset($offset) . "\n";

// 获取时区信息
$timezoneInfo = TimezoneConverter::getTimezoneInfo('Europe/London');
echo "\n伦敦时区信息:\n";
foreach ($timezoneInfo as $key => $value) {
    echo "- $key: $value\n";
}

// 批量转换
$targetTimezones = ['America/New_York', 'Europe/London', 'Asia/Tokyo'];
$conversions = TimezoneConverter::convertMultiple($shanghaiTime, 'Asia/Shanghai', $targetTimezones);

echo "\n批量时区转换 (从上海时间 $shanghaiTime):\n";
foreach ($conversions as $timezone => $time) {
    echo "- $timezone: $time\n";
}

// 获取亚洲时区列表
$asiaTimezones = TimezoneConverter::getTimezoneList('asia');
echo "\n亚洲时区数量: " . count($asiaTimezones) . "\n";
echo "前5个亚洲时区: " . implode(', ', array_slice($asiaTimezones, 0, 5)) . "\n";
?>

高级日期时间应用

1. 日期范围和周期处理

<?php
// 日期范围和周期处理
echo "=== 日期范围和周期处理 ===\n";

class DateRangeManager {
    private $startDate;
    private $endDate;
    
    public function __construct($startDate, $endDate) {
        $this->startDate = new DateTime($startDate);
        $this->endDate = new DateTime($endDate);
        
        if ($this->startDate > $this->endDate) {
            throw new InvalidArgumentException('开始日期不能大于结束日期');
        }
    }
    
    // 获取日期范围内的所有日期
    public function getAllDates($format = 'Y-m-d') {
        $dates = [];
        $current = clone $this->startDate;
        
        while ($current <= $this->endDate) {
            $dates[] = $current->format($format);
            $current->add(new DateInterval('P1D'));
        }
        
        return $dates;
    }
    
    // 获取工作日
    public function getWorkdays($format = 'Y-m-d') {
        $workdays = [];
        $current = clone $this->startDate;
        
        while ($current <= $this->endDate) {
            $dayOfWeek = $current->format('N');
            if ($dayOfWeek >= 1 && $dayOfWeek <= 5) {
                $workdays[] = $current->format($format);
            }
            $current->add(new DateInterval('P1D'));
        }
        
        return $workdays;
    }
    
    // 获取周末
    public function getWeekends($format = 'Y-m-d') {
        $weekends = [];
        $current = clone $this->startDate;
        
        while ($current <= $this->endDate) {
            $dayOfWeek = $current->format('N');
            if ($dayOfWeek >= 6) {
                $weekends[] = $current->format($format);
            }
            $current->add(new DateInterval('P1D'));
        }
        
        return $weekends;
    }
    
    // 获取特定星期几的日期
    public function getDayOfWeek($dayOfWeek, $format = 'Y-m-d') {
        $dates = [];
        $current = clone $this->startDate;
        
        // 找到第一个指定星期几
        while ($current->format('N') != $dayOfWeek && $current <= $this->endDate) {
            $current->add(new DateInterval('P1D'));
        }
        
        // 收集所有指定星期几
        while ($current <= $this->endDate) {
            $dates[] = $current->format($format);
            $current->add(new DateInterval('P7D'));
        }
        
        return $dates;
    }
    
    // 获取月份列表
    public function getMonths($format = 'Y-m') {
        $months = [];
        $current = clone $this->startDate;
        $current->setDate($current->format('Y'), $current->format('n'), 1);
        
        while ($current <= $this->endDate) {
            $months[] = $current->format($format);
            $current->add(new DateInterval('P1M'));
        }
        
        return $months;
    }
    
    // 计算天数差
    public function getDaysDiff() {
        return $this->startDate->diff($this->endDate)->days;
    }
    
    // 判断日期是否在范围内
    public function contains($date) {
        $checkDate = new DateTime($date);
        return $checkDate >= $this->startDate && $checkDate <= $this->endDate;
    }
    
    // 获取范围统计
    public function getStatistics() {
        $allDates = $this->getAllDates();
        $workdays = $this->getWorkdays();
        $weekends = $this->getWeekends();
        
        return [
            'total_days' => count($allDates),
            'workdays' => count($workdays),
            'weekends' => count($weekends),
            'weeks' => ceil(count($allDates) / 7),
            'months' => count($this->getMonths()),
            'start_date' => $this->startDate->format('Y-m-d'),
            'end_date' => $this->endDate->format('Y-m-d')
        ];
    }
}

// 使用日期范围管理器
echo "=== 日期范围管理器示例 ===\n";

$range = new DateRangeManager('2023-08-01', '2023-08-31');

// 获取统计信息
$stats = $range->getStatistics();
echo "8月份统计信息:\n";
foreach ($stats as $key => $value) {
    $labels = [
        'total_days' => '总天数',
        'workdays' => '工作日',
        'weekends' => '周末天数',
        'weeks' => '周数',
        'months' => '月数',
        'start_date' => '开始日期',
        'end_date' => '结束日期'
    ];
    echo "- {$labels[$key]}: $value\n";
}

// 获取所有周一
$mondays = $range->getDayOfWeek(1);
echo "\n8月份所有周一: " . implode(', ', $mondays) . "\n";

// 获取工作日
$workdays = $range->getWorkdays();
echo "8月份工作日数量: " . count($workdays) . "\n";
echo "前5个工作日: " . implode(', ', array_slice($workdays, 0, 5)) . "\n";

// 判断日期是否在范围内
echo "\n日期范围检查:\n";
echo "2023-08-15 在范围内: " . ($range->contains('2023-08-15') ? '是' : '否') . "\n";
echo "2023-09-01 在范围内: " . ($range->contains('2023-09-01') ? '是' : '否') . "\n";
?>

2. 定时任务和周期计算

<?php
// 定时任务和周期计算
echo "=== 定时任务和周期计算 ===\n";

class CronScheduler {
    
    // 解析Cron表达式
    public static function parseCronExpression($expression) {
        $parts = explode(' ', trim($expression));
        
        if (count($parts) !== 5) {
            throw new InvalidArgumentException('Cron表达式必须包含5个部分');
        }
        
        return [
            'minute' => $parts[0],
            'hour' => $parts[1],
            'day' => $parts[2],
            'month' => $parts[3],
            'weekday' => $parts[4]
        ];
    }
    
    // 计算下次执行时间
    public static function getNextRunTime($cronExpression, $fromTime = null) {
        $fromTime = $fromTime ?: new DateTime();
        $cron = self::parseCronExpression($cronExpression);
        
        // 简化版本，只处理基本情况
        $nextRun = clone $fromTime;
        $nextRun->add(new DateInterval('PT1M')); // 从下一分钟开始
        
        // 这里应该有完整的Cron解析逻辑
        // 为了演示，我们返回一个简单的计算结果
        
        return $nextRun;
    }
    
    // 生成常用的Cron表达式
    public static function generateCronExpression($type, $params = []) {
        switch ($type) {
            case 'every_minute':
                return '* * * * *';
            case 'every_hour':
                $minute = $params['minute'] ?? 0;
                return "$minute * * * *";
            case 'daily':
                $hour = $params['hour'] ?? 0;
                $minute = $params['minute'] ?? 0;
                return "$minute $hour * * *";
            case 'weekly':
                $hour = $params['hour'] ?? 0;
                $minute = $params['minute'] ?? 0;
                $weekday = $params['weekday'] ?? 0;
                return "$minute $hour * * $weekday";
            case 'monthly':
                $hour = $params['hour'] ?? 0;
                $minute = $params['minute'] ?? 0;
                $day = $params['day'] ?? 1;
                return "$minute $hour $day * *";
            default:
                throw new InvalidArgumentException('不支持的类型');
        }
    }
    
    // 获取Cron表达式描述
    public static function describeCronExpression($expression) {
        $descriptions = [
            '* * * * *' => '每分钟执行',
            '0 * * * *' => '每小时执行',
            '0 0 * * *' => '每天午夜执行',
            '0 0 * * 0' => '每周日午夜执行',
            '0 0 1 * *' => '每月1号午夜执行',
            '0 0 1 1 *' => '每年1月1号午夜执行'
        ];
        
        if (isset($descriptions[$expression])) {
            return $descriptions[$expression];
        }
        
        $cron = self::parseCronExpression($expression);
        $desc = [];
        
        // 分钟
        if ($cron['minute'] === '*') {
            $desc[] = '每分钟';
        } else {
            $desc[] = "第{$cron['minute']}分钟";
        }
        
        // 小时
        if ($cron['hour'] === '*') {
            $desc[] = '每小时';
        } else {
            $desc[] = "{$cron['hour']}点";
        }
        
        // 日期
        if ($cron['day'] !== '*') {
            $desc[] = "{$cron['day']}号";
        }
        
        // 月份
        if ($cron['month'] !== '*') {
            $desc[] = "{$cron['month']}月";
        }
        
        // 星期
        if ($cron['weekday'] !== '*') {
            $weekdays = ['周日', '周一', '周二', '周三', '周四', '周五', '周六'];
            $desc[] = $weekdays[$cron['weekday']] ?? "星期{$cron['weekday']}";
        }
        
        return implode(' ', $desc) . ' 执行';
    }
}

// 周期任务管理器
class RecurringTaskManager {
    private $tasks = [];
    
    // 添加任务
    public function addTask($name, $cronExpression, $callback) {
        $this->tasks[$name] = [
            'cron' => $cronExpression,
            'callback' => $callback,
            'last_run' => null,
            'next_run' => CronScheduler::getNextRunTime($cronExpression),
            'run_count' => 0
        ];
    }
    
    // 执行到期任务
    public function runDueTasks() {
        $now = new DateTime();
        $executedTasks = [];
        
        foreach ($this->tasks as $name => &$task) {
            if ($task['next_run'] <= $now) {
                // 执行任务
                if (is_callable($task['callback'])) {
                    call_user_func($task['callback']);
                }
                
                // 更新任务信息
                $task['last_run'] = clone $now;
                $task['next_run'] = CronScheduler::getNextRunTime($task['cron'], $now);
                $task['run_count']++;
                
                $executedTasks[] = $name;
            }
        }
        
        return $executedTasks;
    }
    
    // 获取任务状态
    public function getTaskStatus($name = null) {
        if ($name) {
            return $this->tasks[$name] ?? null;
        }
        
        return $this->tasks;
    }
    
    // 移除任务
    public function removeTask($name) {
        unset($this->tasks[$name]);
    }
    
    // 获取下次执行时间
    public function getNextExecutionTime() {
        $nextTimes = [];
        
        foreach ($this->tasks as $name => $task) {
            $nextTimes[$name] = $task['next_run'];
        }
        
        if (empty($nextTimes)) {
            return null;
        }
        
        return min($nextTimes);
    }
}

// 使用定时任务调度器
echo "=== 定时任务调度器示例 ===\n";

// 生成Cron表达式
$cronExpressions = [
    'every_minute' => CronScheduler::generateCronExpression('every_minute'),
    'daily_9am' => CronScheduler::generateCronExpression('daily', ['hour' => 9, 'minute' => 0]),
    'weekly_monday' => CronScheduler::generateCronExpression('weekly', ['hour' => 8, 'minute' => 30, 'weekday' => 1]),
    'monthly_1st' => CronScheduler::generateCronExpression('monthly', ['hour' => 0, 'minute' => 0, 'day' => 1])
];

echo "生成的Cron表达式:\n";
foreach ($cronExpressions as $type => $expression) {
    $description = CronScheduler::describeCronExpression($expression);
    echo "- $type: $expression ($description)\n";
}

// 创建任务管理器
$taskManager = new RecurringTaskManager();

// 添加任务
$taskManager->addTask('backup', '0 2 * * *', function() {
    echo "执行数据库备份任务\n";
});

$taskManager->addTask('cleanup', '0 3 * * 0', function() {
    echo "执行日志清理任务\n";
});

$taskManager->addTask('report', '0 9 1 * *', function() {
    echo "生成月度报告\n";
});

// 获取任务状态
echo "\n任务状态:\n";
$tasks = $taskManager->getTaskStatus();
foreach ($tasks as $name => $task) {
    echo "- $name: 下次执行 " . $task['next_run']->format('Y-m-d H:i:s') . 
         ", 已执行 {$task['run_count']} 次\n";
}

// 获取下次执行时间
$nextExecution = $taskManager->getNextExecutionTime();
if ($nextExecution) {
    echo "\n最近的任务执行时间: " . $nextExecution->format('Y-m-d H:i:s') . "\n";
}
?>

3. 日历和节假日处理

<?php
// 日历和节假日处理
echo "=== 日历和节假日处理 ===\n";

class CalendarManager {
    private $holidays = [];
    
    public function __construct() {
        $this->initializeHolidays();
    }
    
    // 初始化节假日
    private function initializeHolidays() {
        // 固定节假日
        $this->holidays = [
            '01-01' => '元旦',
            '02-14' => '情人节',
            '03-08' => '妇女节',
            '03-12' => '植树节',
            '04-01' => '愚人节',
            '05-01' => '劳动节',
            '05-04' => '青年节',
            '06-01' => '儿童节',
            '07-01' => '建党节',
            '08-01' => '建军节',
            '09-10' => '教师节',
            '10-01' => '国庆节',
            '12-25' => '圣诞节'
        ];
    }
    
    // 添加节假日
    public function addHoliday($date, $name) {
        $key = date('m-d', strtotime($date));
        $this->holidays[$key] = $name;
    }
    
    // 检查是否为节假日
    public function isHoliday($date) {
        $key = date('m-d', strtotime($date));
        return isset($this->holidays[$key]);
    }
    
    // 获取节假日名称
    public function getHolidayName($date) {
        $key = date('m-d', strtotime($date));
        return $this->holidays[$key] ?? null;
    }
    
    // 获取月份日历
    public function getMonthCalendar($year, $month) {
        $firstDay = new DateTime("$year-$month-01");
        $lastDay = clone $firstDay;
        $lastDay->setDate($year, $month, $firstDay->format('t'));
        
        $calendar = [];
        $current = clone $firstDay;
        
        // 填充月初空白
        $startWeekday = $current->format('N') % 7; // 0=周日, 1=周一...
        for ($i = 0; $i < $startWeekday; $i++) {
            $calendar[] = null;
        }
        
        // 填充月份天数
        while ($current <= $lastDay) {
            $dateStr = $current->format('Y-m-d');
            $calendar[] = [
                'date' => $dateStr,
                'day' => $current->format('j'),
                'is_weekend' => $current->format('N') >= 6,
                'is_holiday' => $this->isHoliday($dateStr),
                'holiday_name' => $this->getHolidayName($dateStr),
                'is_today' => $dateStr === date('Y-m-d')
            ];
            $current->add(new DateInterval('P1D'));
        }
        
        return [
            'year' => $year,
            'month' => $month,
            'month_name' => $firstDay->format('F'),
            'days' => $calendar,
            'weeks' => array_chunk($calendar, 7)
        ];
    }
    
    // 获取年份所有节假日
    public function getYearHolidays($year) {
        $yearHolidays = [];
        
        foreach ($this->holidays as $dateKey => $name) {
            $fullDate = "$year-$dateKey";
            $yearHolidays[] = [
                'date' => $fullDate,
                'name' => $name,
                'weekday' => date('l', strtotime($fullDate))
            ];
        }
        
        return $yearHolidays;
    }
    
    // 计算工作日（排除周末和节假日）
    public function calculateWorkdays($startDate, $endDate) {
        $start = new DateTime($startDate);
        $end = new DateTime($endDate);
        $workdays = 0;
        
        $current = clone $start;
        while ($current <= $end) {
            $dateStr = $current->format('Y-m-d');
            $dayOfWeek = $current->format('N');
            
            // 不是周末且不是节假日
            if ($dayOfWeek < 6 && !$this->isHoliday($dateStr)) {
                $workdays++;
            }
            
            $current->add(new DateInterval('P1D'));
        }
        
        return $workdays;
    }
    
    // 获取下一个工作日
    public function getNextWorkday($date = null) {
        $current = new DateTime($date ?: 'now');
        $current->add(new DateInterval('P1D'));
        
        while (true) {
            $dateStr = $current->format('Y-m-d');
            $dayOfWeek = $current->format('N');
            
            if ($dayOfWeek < 6 && !$this->isHoliday($dateStr)) {
                return $current;
            }
            
            $current->add(new DateInterval('P1D'));
        }
    }
    
    // 农历转换（简化版）
    public function getLunarDate($date) {
        // 这里应该有完整的农历转换算法
        // 为了演示，返回模拟数据
        return [
            'lunar_year' => '癸卯年',
            'lunar_month' => '六月',
            'lunar_day' => '十八',
            'zodiac' => '兔',
            'solar_term' => '立秋'
        ];
    }
}

// 使用日历管理器
echo "=== 日历管理器示例 ===\n";

$calendar = new CalendarManager();

// 检查节假日
$testDates = ['2023-01-01', '2023-05-01', '2023-10-01', '2023-08-05'];
echo "节假日检查:\n";
foreach ($testDates as $date) {
    $isHoliday = $calendar->isHoliday($date);
    $holidayName = $calendar->getHolidayName($date);
    echo "- $date: " . ($isHoliday ? "节假日 ($holidayName)" : "普通日期") . "\n";
}

// 计算工作日
$workdays = $calendar->calculateWorkdays('2023-08-01', '2023-08-31');
echo "\n2023年8月工作日数量: $workdays 天\n";

// 获取下一个工作日
$nextWorkday = $calendar->getNextWorkday('2023-08-05');
echo "2023-08-05的下一个工作日: " . $nextWorkday->format('Y-m-d') . "\n";

// 获取月份日历
$monthCalendar = $calendar->getMonthCalendar(2023, 8);
echo "\n2023年8月日历:\n";
echo "年份: {$monthCalendar['year']}, 月份: {$monthCalendar['month']} ({$monthCalendar['month_name']})\n";

echo "日历布局:\n";
echo "日  一  二  三  四  五  六\n";
foreach ($monthCalendar['weeks'] as $week) {
    foreach ($week as $day) {
        if ($day === null) {
            echo "   ";
        } else {
            $marker = '';
            if ($day['is_today']) $marker .= '*';
            if ($day['is_holiday']) $marker .= 'H';
            if ($day['is_weekend']) $marker .= 'W';
            
            printf("%2d%s", $day['day'], $marker ? "($marker)" : "   ");
        }
    }
    echo "\n";
}

echo "\n图例: * = 今天, H = 节假日, W = 周末\n";

// 获取年度节假日
$yearHolidays = $calendar->getYearHolidays(2023);
echo "\n2023年节假日列表:\n";
foreach (array_slice($yearHolidays, 0, 5) as $holiday) {
    echo "- {$holiday['date']} ({$holiday['weekday']}): {$holiday['name']}\n";
}

// 农历信息
$lunarInfo = $calendar->getLunarDate('2023-08-05');
echo "\n2023-08-05 农历信息:\n";
foreach ($lunarInfo as $key => $value) {
    $labels = [
        'lunar_year' => '农历年',
        'lunar_month' => '农历月',
        'lunar_day' => '农历日',
        'zodiac' => '生肖',
        'solar_term' => '节气'
    ];
    echo "- {$labels[$key]}: $value\n";
}
?>

性能优化和最佳实践

<?php
// 日期时间性能优化
echo "=== 性能优化和最佳实践 ===\n";

class DateTimeOptimizer {
    
    // 缓存时区对象
    private static $timezoneCache = [];
    
    // 获取缓存的时区对象
    public static function getTimezone($timezone) {
        if (!isset(self::$timezoneCache[$timezone])) {
            self::$timezoneCache[$timezone] = new DateTimeZone($timezone);
        }
        
        return self::$timezoneCache[$timezone];
    }
    
    // 批量日期格式化
    public static function formatDates($dates, $format = 'Y-m-d H:i:s') {
        $formatted = [];
        
        foreach ($dates as $date) {
            if ($date instanceof DateTime) {
                $formatted[] = $date->format($format);
            } elseif (is_numeric($date)) {
                $formatted[] = date($format, $date);
            } else {
                $formatted[] = date($format, strtotime($date));
            }
        }
        
        return $formatted;
    }
    
    // 性能测试
    public static function benchmarkDateOperations($iterations = 1000) {
        $results = [];
        
        // 测试 DateTime vs date()
        $start = microtime(true);
        for ($i = 0; $i < $iterations; $i++) {
            $dt = new DateTime();
            $formatted = $dt->format('Y-m-d H:i:s');
        }
        $results['DateTime'] = microtime(true) - $start;
        
        $start = microtime(true);
        for ($i = 0; $i < $iterations; $i++) {
            $formatted = date('Y-m-d H:i:s');
        }
        $results['date()'] = microtime(true) - $start;
        
        // 测试时区转换
        $start = microtime(true);
        for ($i = 0; $i < $iterations; $i++) {
            $dt = new DateTime('now', new DateTimeZone('Asia/Shanghai'));
        }
        $results['new_timezone'] = microtime(true) - $start;
        
        $start = microtime(true);
        for ($i = 0; $i < $iterations; $i++) {
            $dt = new DateTime('now', self::getTimezone('Asia/Shanghai'));
        }
        $results['cached_timezone'] = microtime(true) - $start;
        
        return $results;
    }
    
    // 内存使用优化
    public static function optimizeMemoryUsage() {
        $tips = [
            '1. 重用DateTime对象而不是创建新对象',
            '2. 缓存DateTimeZone对象',
            '3. 使用时间戳进行简单计算',
            '4. 避免在循环中创建DateTime对象',
            '5. 使用静态方法减少对象创建开销'
        ];
        
        return $tips;
    }
    
    // 最佳实践建议
    public static function getBestPractices() {
        return [
            'timezone' => [
                '总是明确指定时区',
                '在应用启动时设置默认时区',
                '存储UTC时间，显示时转换为本地时区',
                '缓存时区对象避免重复创建'
            ],
            'formatting' => [
                '使用ISO 8601格式进行数据交换',
                '为用户界面提供本地化格式',
                '避免在数据库中存储格式化字符串',
                '使用常量定义常用格式'
            ],
            'calculation' => [
                '使用DateTime类进行复杂计算',
                '简单计算可以使用时间戳',
                '注意闰年和月份天数差异',
                '处理夏令时变化'
            ],
            'validation' => [
                '验证用户输入的日期格式',
                '检查日期范围的合理性',
                '处理无效日期的异常情况',
                '考虑不同地区的日期格式习惯'
            ]
        ];
    }
}

// 使用性能优化器
echo "=== 性能优化器示例 ===\n";

// 性能测试
$benchmarkResults = DateTimeOptimizer::benchmarkDateOperations(100);
echo "性能测试结果 (100次迭代):\n";
foreach ($benchmarkResults as $method => $time) {
    echo "- $method: " . round($time * 1000, 2) . "ms\n";
}

// 批量格式化
$dates = [
    new DateTime(),
    time(),
    '2023-08-05 15:30:00',
    strtotime('+1 day')
];

$formatted = DateTimeOptimizer::formatDates($dates, 'Y-m-d H:i:s');
echo "\n批量格式化结果:\n";
foreach ($formatted as $i => $date) {
    echo "- 日期 $i: $date\n";
}

// 内存优化建议
echo "\n内存优化建议:\n";
$memoryTips = DateTimeOptimizer::optimizeMemoryUsage();
foreach ($memoryTips as $tip) {
    echo "- $tip\n";
}

// 最佳实践
echo "\n最佳实践建议:\n";
$bestPractices = DateTimeOptimizer::getBestPractices();
foreach ($bestPractices as $category => $practices) {
    $categoryNames = [
        'timezone' => '时区处理',
        'formatting' => '格式化',
        'calculation' => '计算',
        'validation' => '验证'
    ];
    
    echo "\n{$categoryNames[$category]}:\n";
    foreach ($practices as $practice) {
        echo "  - $practice\n";
    }
}

// 常用日期格式常量
class DateFormats {
    const ISO_DATE = 'Y-m-d';
    const ISO_DATETIME = 'Y-m-d H:i:s';
    const ISO_DATETIME_MS = 'Y-m-d H:i:s.u';
    const RFC_2822 = 'r';
    const ATOM = 'c';
    const CHINESE_DATE = 'Y年m月d日';
    const CHINESE_DATETIME = 'Y年m月d日 H:i:s';
    const US_DATE = 'm/d/Y';
    const EU_DATE = 'd/m/Y';
    const TIME_12H = 'g:i A';
    const TIME_24H = 'H:i:s';
}

echo "\n常用日期格式常量:\n";
$now = new DateTime();
$formats = [
    'ISO_DATE' => DateFormats::ISO_DATE,
    'ISO_DATETIME' => DateFormats::ISO_DATETIME,
    'CHINESE_DATE' => DateFormats::CHINESE_DATE,
    'US_DATE' => DateFormats::US_DATE,
    'TIME_12H' => DateFormats::TIME_12H
];

foreach ($formats as $name => $format) {
    echo "- $name: " . $now->format($format) . "\n";
}
?>

总结

通过本文的学习，我们全面掌握了PHP日期时间处理的各个方面：

关键要点

1. 基础操作: 掌握了date()函数、DateTime类和时间戳的使用
2. 时区处理: 学会了时区转换和多时区应用开发
3. 高级应用: 了解了日期范围、定时任务和日历系统的实现
4. 性能优化: 掌握了日期时间操作的性能优化技巧

最佳实践

• 总是明确指定时区，避免时区混乱
• 使用DateTime类处理复杂的日期计算
• 缓存时区对象提高性能
• 存储UTC时间，显示时转换为本地时区
• 验证用户输入的日期格式

实用技巧

• 使用相对时间格式提高用户体验
• 实现工作日计算排除周末和节假日
• 构建灵活的定时任务调度系统
• 处理不同地区的日期格式习惯
• 优化大量日期操作的性能

掌握这些日期时间处理技巧，将帮助你构建更专业、更用户友好的时间相关功能。记住，日期时间处理看似简单，但涉及时区、格式化、计算等多个方面，需要仔细考虑各种边界情况。