DateTime::getLastErrors
These functions makes sure that adding months or years always ends up in the month you would expect. Works for positive and negative values
<?php
$date=new DateTime();
$date->setDate(2008,2,29);
function addMonths($date,$months){
$init=clone $date;
$modifier=$months.' months';
$back_modifier =-$months.' months';
$date->modify($modifier);
$back_to_init= clone $date;
$back_to_init->modify($back_modifier);
while($init->format('m')!=$back_to_init->format('m')){
$date->modify('-1 day') ;
$back_to_init= clone $date;
$back_to_init->modify($back_modifier);
}
/*
if($months<0&&$date->format('m')>$init->format('m'))
while($date->format('m')-12-$init->format('m')!=$months%12)
$date->modify('-1 day');
else
if($months>0&&$date->format('m')<$init->format('m'))
while($date->format('m')+12-$init->format('m')!=$months%12)
$date->modify('-1 day');
else
while($date->format('m')-$init->format('m')!=$months%12)
$date->modify('-1 day');
*/
}
function addYears($date,$years){
$init=clone $date;
$modifier=$years.' years';
$date->modify($modifier);
while($date->format('m')!=$init->format('m'))
$date->modify('-1 day');
}
addMonths($date,-1);
addYears($date,3);
echo $date->format('F j,Y');
?>
DateTime::modify
date_modify
(PHP 5 >= 5.2.0)
DateTime::modify -- date_modify — Alters the timestamp
Description
Object oriented style
Procedural style
Alter the timestamp of a DateTime object by incrementing or decrementing in a format accepted by strtotime().
Parameters
-
object -
Procedural style only: A DateTime object returned by date_create(). The function modifies this object.
-
modify -
A date/time string. Valid formats are explained in Date and Time Formats.
Return Values
Returns the DateTime object for method chaining or FALSE on failure.
Changelog
| Version | Description |
|---|---|
| 5.3.6 | Absolute date/time statements now take effect. Previously, only relative parts were used. |
| 5.3.0 | Changed the
return value on success from NULL to DateTime. |
Examples
Example #1 DateTime::modify() example
Object oriented style
<?php
$date = new DateTime('2006-12-12');
$date->modify('+1 day');
echo $date->format('Y-m-d');
?>
Procedural style
<?php
$date = date_create('2006-12-12');
date_modify($date, '+1 day');
echo date_format($date, 'Y-m-d');
?>
The above examples will output:
2006-12-13
Example #2 Beware when adding or subtracting months
<?php
$date = new DateTime('2000-12-31');
$date->modify('+1 month');
echo $date->format('Y-m-d') . "\n";
$date->modify('+1 month');
echo $date->format('Y-m-d') . "\n";
?>
The above example will output:
2001-01-31 2001-03-03
See Also
- strtotime() - Parse about any English textual datetime description into a Unix timestamp
- DateTime::add() - Adds an amount of days, months, years, hours, minutes and seconds to a DateTime object
- DateTime::sub() - Subtracts an amount of days, months, years, hours, minutes and seconds from a DateTime object
- DateTime::setDate() - Sets the date
- DateTime::setISODate() - Sets the ISO date
- DateTime::setTime() - Sets the time
- DateTime::setTimestamp() - Sets the date and time based on an Unix timestamp
add a note
User Contributed Notes
DateTime::modify - [3 notes]
jenspj at msn dot com ¶
1 year ago
Jenny jsimonds@atomic jet packs dot com ¶
1 year ago
Note: This method modifies the object in-place. So if you want to calculate a new date but assign the new value to a different object, this will NOT work:
<?php
$numMinutes = 25;
$oDateA = new DateTime('2012-01-01 12:00:00');
print "
Original:<br>
oDateA = {$oDateA->format('Y-m-d H-i-s')}<br>
";
$oDateB = $oDateA->modify ("+{$numMinutes} minutes");
print "
plus {$numMinutes} minutes:<br>
oDateA = {$oDateA->format('Y-m-d H-i-s')}<br>
oDateB = {$oDateB->format('Y-m-d H-i-s')}<br>
";
?>
...produces this:
oDateA = 2012-01-01 12-00-00
plus 25 minutes:
oDateA = 2012-01-01 12-25-00
oDateB = 2012-01-01 12-25-00
Use something like this instead:
<?php
$numMinutes = 25;
$oDateA = new DateTime('2012-01-01 12:00:00');
print "
<p>
Original:<br>
oDateA = {$oDateA->format('Y-m-d H-i-s')}<br>
";
$oDateB = clone $oDateA;
$oDateB->modify ("+{$numMinutes} minutes");
print "
plus {$numMinutes} minutes:<br>
oDateA = {$oDateA->format('Y-m-d H-i-s')}<br>
oDateB = {$oDateB->format('Y-m-d H-i-s')}<br>
";
?>
... produces this:
oDateA = 2012-01-01 12-00-00
plus 25 minutes:
oDateA = 2012-01-01 12-00-00
oDateB = 2012-01-01 12-25-00
tom at r dot je ¶
4 years ago
If you want to find the next working day (assuming mon-fri) you can use this:
<?php
$d = new DateTime();
$day = $d->format('w');
if ($day == 0 || $day >= 5) $d->modify('+' . ((7-$day+1) % 7) . ' days');
else $d->modify('+1 day');
?>