//获得本周（本天）时间戳的起始和结束
//本周星期一时间戳
$monday = mktime(0, 0, 0,
date("m",strtotime("last Monday")) , date("d",strtotime("last
Monday")), date("Y",strtotime("last Monday")));
//本周星期日时间戳
$sunday =
mktime(0, 0, 0, date("m",strtotime("next Sunday")) ,
date("d",strtotime("next Sunday")), date("Y",strtotime("next Sunday")));
//今日起始时间戳
$lastSecToday = mktime(0, 0, 0, date("m") ,
date("d")+1, date("Y"))-1;
//今日结束时间戳
$firstSecToday = mktime(0, 0, 0,
date("m") , date("d"), date("Y"));
原文：http://www.cnblogs.com/kafeijiu/p/3747753.html