PHP check if two Datetimes are not on the same calendar day

Question

I have two Datetimes like this (the dates being actually $vars)

$startTime = \\DateTime::createFromFormat(\'Y/m/d H:i\', \'2015/01/01 23:00\');
$endTime = \\Date         


        

Answer 1

I think this is one of the few situations where the use of strings for date calculations is justified:

function onDifferentDays(\DateTimeInterface $startTime, \DateTimeInterface $endTime){
    return $startTime->format('Y-m-d')!==$endTime->format('Y-m-d');
}

This code should be easy to extend to include time zone.

There're other alternatives but I don't think they're normally worth the effort:

1. Compare element by element (day, month and year):

   • The PHP DateTime class doesn't offer dedicated functions, only format().

2. Normalize both dates to a common time and compare with == (not ===):

   • Unless you're using immutable objects you need to clone input or expect side effects

   • You also need to ensure that time exists in the active time zone though midnight is probably safe enough.

Whatever, YMMV ;-)