//运行结果(年月日，“-”间隔)：2014-09-12 echo date( 'Y-m-d' , strtotime( date( 'Y-m-d' , time() - 86400 ) ) ) ; //运行结果(当前日期前一天的年月日，“-”间隔)：2014-09-11 echo date( 'Ymd' , time() ) ; //运行结果(年月日，无间隔)：20140912 echo date( 'm-d' , time() ) ; //运行结果(月日，“-”间隔)：09-12 echo str_replace( "-" , "月" , date( 'm-d' , time() -date( 'w' , time() ) * 86400 ) ) ."日"; //运行结果(月日，汉字显示间隔)：09月12日 echo date( 'w' , time() ) ; //运行结果(星期几)：5 echo time() ; //运行结果(当前日期时间的秒数)：1410503809 echo strtotime( date( 'Y-m-d' , time() ) ) ; //运行结果(当前日期秒数，具体到天)：1410503809 echo date( 'Y-m-d' , strtotime( date( 'Y-m-d' , time() ) ) -date( 'w' , strtotime( date( 'Y-m-d' , time() ) ) ) * 86400 ) ; //运行结果(当前日期所属自然周的起始日期即周日的日期，具体到天，“-”间隔)：2014-09-07

//php获取今日开始时间戳和结束时间戳
$beginToday=mktime(0,0,0,date('m'),date('d'),date('Y'));
$endToday=mktime(0,0,0,date('m'),date('d')+1,date('Y'))-1;
//php获取昨日起始时间戳和结束时间戳
$beginYesterday=mktime(0,0,0,date('m'),date('d')-1,date('Y'));
$endYesterday=mktime(0,0,0,date('m'),date('d'),date('Y'))-1;
//php获取上周起始时间戳和结束时间戳
$beginLastweek=mktime(0,0,0,date('m'),date('d')-date('w')+1-7,date('Y'));
$endLastweek=mktime(23,59,59,date('m'),date('d')-date('w')+7-7,date('Y'));
//php获取本月起始时间戳和结束时间戳
$beginThismonth=mktime(0,0,0,date('m'),1,date('Y'));
$endThismonth=mktime(23,59,59,date('m'),date('t'),date('Y'));

/**date 2015-04-11 * author http://www.lai18.com echo date ( "Ymd" ,strtotime( "now" )), "\n" ; echo date ( "Ymd" ,strtotime( "-1 week Monday" )), "\n" ; echo date ( "Ymd" ,strtotime( "-1 week Sunday" )), "\n" ; echo date ( "Ymd" ,strtotime( "+0 week Monday" )), "\n" ; echo date ( "Ymd" ,strtotime( "+0 week Sunday" )), "\n" ; echo "*********第几个月:" ; echo date ( 'n' ); echo "*********本周周几:" ; echo date ( "w" ); echo "*********本月天数:" ; echo date ( "t" ); echo "*********" ; echo '<br>上周起始时间:<br>' ; echo date ( "Y-m-d H:i:s" ,mktime( 0 , 0 , 0 , date ( "m" ), date ( "d" )- date ( "w" )+ 1 - 7 , date ( "Y" ))), "\n" ; echo date ( "Y-m-d H:i:s" ,mktime( 23 , 59 , 59 , date ( "m" ), date ( "d" )- date ( "w" )+ 7 - 7 , date ( "Y" ))), "\n" ; echo '<br>本周起始时间:<br>' ; echo date ( "Y-m-d H:i:s" ,mktime( 0 , 0 , 0 , date ( "m" ), date ( "d" )- date ( "w" )+ 1 , date ( "Y" ))), "\n" ; echo date ( "Y-m-d H:i:s" ,mktime( 23 , 59 , 59 , date ( "m" ), date ( "d" )- date ( "w" )+ 7 , date ( "Y" ))), "\n" ; echo '<br>上月起始时间:<br>' ; echo date ( "Y-m-d H:i:s" ,mktime( 0 , 0 , 0 , date ( "m" )- 1 , 1 , date ( "Y" ))), "\n" ; echo date ( "Y-m-d H:i:s" ,mktime( 23 , 59 , 59 , date ( "m" ) , 0 , date ( "Y" ))), "\n" ; echo '<br>本月起始时间:<br>' ; echo date ( "Y-m-d H:i:s" ,mktime( 0 , 0 , 0 , date ( "m" ), 1 , date ( "Y" ))), "\n" ; echo date ( "Y-m-d H:i:s" ,mktime( 23 , 59 , 59 , date ( "m" ), date ( "t" ), date ( "Y" ))), "\n" ; $season = ceil (( date ( 'n' ))/ 3 ); //当月是第几季度 echo '<br>本季度起始时间:<br>' ; echo date ( 'Y-m-d H:i:s' , mktime( 0 , 0 , 0 , $season *3 - 3 + 1 , 1 , date ( 'Y' ))), "\n" ; echo date ( 'Y-m-d H:i:s' , mktime( 23 , 59 , 59 , $season *3 , date ( 't' ,mktime( 0 , 0 , 0 , $season *3 , 1 , date ( "Y" ))), date ( 'Y' ))), "\n" ; $season = ceil (( date ( 'n' ))/ 3 )- 1 ; //上季度是第几季度 echo '<br>上季度起始时间:<br>' ; echo date ( 'Y-m-d H:i:s' , mktime( 0 , 0 , 0 , $season *3 - 3 + 1 , 1 , date ( 'Y' ))), "\n" ; echo date ( 'Y-m-d H:i:s' , mktime( 23 , 59 , 59 , $season *3 , date ( 't' ,mktime( 0 , 0 , 0 , $season *3 , 1 , date ( "Y" ))), date ( 'Y' ))), "\n" ;