PHP date before or after day

PHP Judge today's day before, or before and after how many days of code

<?php Date_default_timezone_set ('PRC');//Default time zoneEcho"Today:", Date ("y-m-d", time ()),"<br>"; Echo"Today:", Date ("y-m-d", Strtotime ("June")),"<br>"; Echo"yesterday:", Date ("y-m-d", Strtotime ("-1 Day")),"<br>"; Echo"Tomorrow:", Date ("y-m-d", Strtotime ("+1 Day")),"<br>"; Echo"after a week:", Date ("y-m-d", Strtotime ("+1 Week")),"<br>"; Echo"2 days a week, four hours, two seconds later:", Date ("y-m-d g:h:s", Strtotime ("+1 Week 2 days 4 hours 2 seconds")),"<br>"; Echo"next week four:", Date ("y-m-d", Strtotime ("next Thursday")),"<br>"; Echo"Last Monday:". Date ("y-m-d", Strtotime ("Last Monday"))."<br>"; Echo"one months ago:". Date ("y-m-d", Strtotime ("Last month"))."<br>"; Echo"after one months:". Date ("y-m-d", Strtotime ("+1 Month"))."<br>"; Echo"ten years later:". Date ("y-m-d", Strtotime ("+10 Year"))."<br>"; ?>

PHP determines how many days a date is from today

<? php Echo (strtotime ('

PHP date before or after day