How to check if the dates are not the same - php

Question

I try to write a script that can calculate the difference between two dates, in days, and the diff does not behave as I need to.
More specific, lets say we have the following two date/times:
2015-03-18 23:00
2015-03-19 02:00
The actual time difference is four hours, and in this terms the diff works fine !
But what I like to know is, if the calendar date has been change, and what is the actual difference.
So in the example above, the calendar dates having 1 day difference.
In the following example
2015-03-18 23:00
2015-03-21 02:00
I have three days difference. So how can I calculate this date difference ?
At the moment I use the following code:
$datetime1 = new DateTime('2009-10-11 23:30');
$datetime2 = new DateTime('2009-10-12 02:30');
$interval = $datetime1->diff($datetime2);
echo "<pre>";
print_r($interval);
echo "</pre>";
and the result is the following:
DateInterval Object
(
[y] => 0
[m] => 0
[d] => 0
[h] => 3
[i] => 0
[s] => 0
[weekday] => 0
[weekday_behavior] => 0
[first_last_day_of] => 0
[invert] => 0
[days] => 0
[special_type] => 0
[special_amount] => 0
[have_weekday_relative] => 0
[have_special_relative] => 0
)
Is there any idea ? Thanks ...

Answer 1

A really simple solution
Notice: this will only work if the days are in the same month.
$datetime1 = new DateTime('2015-03-18 23:00');
$datetime2 = new DateTime('2015-03-21 02:00');
$difference = $datetime2->format('d') - $datetime1->format('d'); //3
Clean solution
You could remove everything from the date, but the year, month and day and use diff() as you already did.
$datetime1 = new DateTime('2015-03-18 23:00');
$datetime2 = new DateTime('2015-03-21 02:00');
$datetime1modified = new DateTime($datetime1->format('Y-m-d'));
$datetime2modified = new DateTime($datetime2->format('Y-m-d'));
$difference = $datetime1modified->diff($datetime2modified)->d; //3

Answer 2

you surely could use a function like this:
$time1 = strtotime("2008-12-13 10:42:00");
$time2 = strtotime("2010-10-20 08:10:00");
$diff = $time2-$time1;
// the difference in int. then you can divide by 60,60,24 and
// so on to get the h:m:s out of it
or if you more into the build in php functions then something like this might suit your needs:
$date_a = new DateTime('2010-10-20 08:10:00');
$date_b = new DateTime('2008-12-13 10:42:00');
$interval = date_diff($date_a,$date_b);
echo $interval->format('%h:%i:%s');
best regards.

Answer 3

What you can do is remove the Time from each of the dates and then calculate.
example:
$datetime1 ='2009-10-11 23:30';
$datetime2 = '2009-10-12 02:30';
$date1_explode = explode($datetime1,' ');
$date1_explode = explode($datetime1,' ');
$date = $date1_explode[1];
$date = $date2_explode[1];
$date1 = new DateTime($datetime1);
$date2 = new DateTime($datetime1);
$interval = $date1->diff($date2);
echo "<pre>";
print_r($interval);
echo "</pre>";

Answer 4

If you don't care about the hours and want to know only if the date changed you can try to diff the dates after you set them to the same hour:
$datetime1 = new DateTime('2009-10-11 23:30');
$datetime2 = new DateTime('2009-10-12 02:30');
// Work on duplicates to not change the original objects if they are needed later
$date1 = clone $datetime1;
$date2 = clone $datetime2;
// Set the same hour on both $date1 and $date2
$date1->setTime(0, 0, 0);
$date2->setTime(0, 0, 0);
// Now you can simply compare $date1 to $date2 to see if they are equal
if ($date1 == $date2) {
echo('$datetime1 and $datetime2 are on the same date.');
} else {
echo('$datetime1 and $datetime2 are on different dates.');
}
// Or you can compute the difference
$diff = $date2->diff($date1);
// and format it as you like
echo('There are '.$diff->format('%d').' days between '.$date1.' and '.$date2);