PHP日期相关类

<?php
class Date{
    /**
     * 获取某年某月的开始结束日期
     * @param int $year
     * @param int $month
     */
    public function getMonthStartEnd($year, $month){
        $firstday = date('Y-m-d', mktime(0, 0, 0, $month, 1,$year));
        $lastday = date('Y-m-d', mktime(0, 0, 0,$month+1,1,$year)-1);
        $return = array(
                'start'=>$firstday,
                'end'=>$lastday,
                'stime'=>strtotime($firstday),
                'etime'=>strtotime($lastday)
        );
        return $return;
    }
    
    /**
     * 获取某年某周的开始结束日期
     * @param int $year
     * @param int $week 1~52
     */
    public function getWeekStartEnd($year,$week){
        $weeks = date("W", mktime(0, 0, 0, 12, 28, $year));
        if ($week > $weeks || $week <= 0)
        {
            $week = 1;
        }
        if ($week < 10)
        {
            $week = '0' . $week;
        }
        $time['stime'] = strtotime($year . 'W' . $week);
        $time['etime'] = strtotime('+1 week -1 day', $time['stime']);
        $time['start'] = date('Y-m-d',$time['stime']);
        $time['end'] = date('Y-m-d',$time['etime']);
        return $time;
    }
}