Summary of issues related to PHP time calculation_php skills

the examples in this article summarize issues related to php time calculation. share it with everyone for your reference, the details are as follows:

1. get the date three months ago with php

<?php header("content-type: text/html; charset=utf-8");?>
<?php
$s_sdate=date("y-m-d"); //当前时间
$moth_day=90; //月份 (转为天数)
$s_edate=date("y-m-d",(strtotime($s_sdate)-$moth_day*84600));
echo $moth_day."前的日期为".$s_edate;
?>

2. 30 days after the calculation date

you can use strtotime. php provides a super simple way to complete work that would otherwise require dozens of lines of code.

first convert a date into a unix timestamp

$t = time(); // 当前时间戳
$t = strtotime("+30 days", $t); // 30天后的时间戳
echo date("y-m-d", $t); // 格式化日期

3. convert the timestamps of 2 dates...and then subtract them

$t1 = strtotime("2009-08-19");
$t2 = strtotime("2009-08-20");
$t = $t2 - $t1; // 相差天数的秒
echo (int)($t / 86400)

4. determine whether it is this week

$date = "2008-12-08";
if (isCurrentWeeks($date)) {
  echo $date."是本星期";
} else {
  echo $date."不是本星期";
}
function isCurrentWeeks($d) {
  return (date("W",strtotime($d))==date("W",strtotime("now")));
}

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i hope this article will be helpful to everyone in php programming.