date_default_timezone_set('PRC');
date("Y-m-d H:i:s", strtotime(" +2 year"));
date("Y-m-d H:i:s", strtotime(" +2 month"));
date("Y-m-d H:i:s", strtotime(" +2 week"));  
date("Y-m-d H:i:s", strtotime(" +2 day"));  
date("Y-m-d H:i:s", strtotime(" +2 hour"));  
date("Y-m-d H:i:s", strtotime(" +2 minute"));  
date("Y-m-d H:i:s", strtotime(" +2 second"));  
  
echo date("Ymd",strtotime("now"));
echo date("Ymd",strtotime("-1 week Monday"));
echo date("Ymd",strtotime("-1 week Sunday"));
echo date("Ymd",strtotime("+0 week Monday"));  
echo date("Ymd",strtotime("+0 week Sunday"));  
  
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:<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:<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:<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:<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:<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:<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";