DateTime::createFromFormat
The DateInterval format unfortunately leads to inconsitencies:
<?php
$start = new DateTime('2009-01-01 00:00:00'); // 31 days
$time_span = $start->diff(new DateTime('2009-02-01 00:00:00'));
var_dump($time_span); // returns '1 month'
$start = new DateTime('2009-02-01 00:00:00'); //28 days
$time_span = $start->diff(new DateTime('2009-03-01 00:00:01'));
var_dump($time_span); // returns '1 month'
?>
Of course it is possible to guess what does DateTime mean for a month, but in such case the invoking program should take care of month lengths and leap years (imagine counting days between dates years appart) - DateTime class is supposed to do that. In my opinion this function should return a value in seconds (or any other stable unit). Afterwards the program would have to convert the value as needed, but the value would be exact.
DateTime::diff
(PHP 5 >= 5.3.0)
DateTime::diff — Returns the difference between two DateTime objects
Description
Returns the difference between two DateTime objects.
Parameters
- datetime
-
The date to compare to.
- absolute
-
Whether to return absolute difference.
Return Values
The difference between two dates.
add a note
User Contributed NotesDateTime::diff
andarin2 at yahoo dot com
18-Nov-2009 10:32
18-Nov-2009 10:32
Anonymous
04-Aug-2009 12:17
04-Aug-2009 12:17
You don't need to calculate the exact difference if you just want to know what date comes earlier:
<?php
date_default_timezone_set('Europe/Madrid');
$d1 = new DateTime('1492-01-01');
$d2 = new DateTime('1492-12-31');
var_dump($d1 < $d2);
var_dump($d1 > $d2);
var_dump($d1 == $d2);
?>
bool(true)
bool(false)
bool(false)
thinice at gmail dot com
17-Jul-2009 07:29
17-Jul-2009 07:29
Some stuff to help you get started:
<?php
// See what's inside
$oDT = new DateTime();
var_dump($oDT);
?>
To do a date difference:
<?php
$oDT = new DateTime(); //Sets the object to now
$oDTDiff = $oDT->diff(new DateTime('2009-08-18 00:00:01'));
var_dump($oDTDiff);
echo "Days of difference: ". $oDTDiff->days;
?>