使用日期对象计算日期时间的最准确方法

Question

i am working on an access site, paying members will get exactly 3 months access period to the site. the issue therefore is how to calculate an exact 3 month date period.

i.e, some months are 28 days, others are 31 days; normal years is 365 but lunar year is 354 days.

i was thinking of converting the date to a UNIX timestamps and then calculating 3 months in seconds. But i am not sure whether this is the most efficient and accurate way to do it.

below is my proposal , i would really appreciate some advice on it;

timestamp when the clocks starts

$UNIXtimeStampNow   =   new \DateTime("now"))->format('U')

calculating 3 months from date:

  $numberDaysInMonth  = 30.41 = 365/ 12   //number of days in months

  $numberSecondsInDay  = 86400; //number seconds in a day

 $secondsIn3Months  = ($numberDaysInMonth * $numberSecondsInDay) * 3  //number seconds in 3 months

    new \DateTime("$secondsIn3Months"); //convert back to date object

like i said, this is the best i came up with, but i suspect that its not accurate.

would really appropriate some advice

Answer 1

As I said in my comment, just use the DateTime object's add() method with a DateInterval

$d = new \DateTime("now");
$d->add(new \DateInterval('P3M'));
echo $d->format('Y-m-d H:i:s');