php中时间运算

$tomorrow = date( “Y-m-d”, mktime(0,0,0,4,1+1,2005));

$tomorrow = date( “Y-m-d”, mktime(0,0,0,date(”m”) ,date(”d”)+1,date(”Y”))); //明天

$yesterday = date( “Y-m-d”, mktime(0,0,0,date(”m”) ,date(”d”)-1,date(”Y”))); //昨天

$lastmonth = date( “Y-m-d”, mktime(0,0,0,date(”m”)-1,date(”d”), date(”Y”))); //上一个月

$nextyear = date( “Y-m-d”, mktime(0,0,0,date(”m”), date(”d”, date(”Y”)+1)); //下一年

$today = date(”Ymd”,strtotime (”+1 day”));

$date1=”2006-08-09″;
echo date(’Y-m-d’,strtotime(”$date1 +5 day”)); //相应地,要增加月,年,将day改成month或year即可