(PHP 5 >= 5.5.0, PHP 7, PHP 8)
DateTimeImmutable::modify — Creates a new object with modified timestamp
Creates a new DateTimeImmutable object with modified timestamp. The original object is not modified.
modifierA date/time string. Valid formats are explained in Date and Time Formats.
   Returns DateTimeImmutable on success.
   Procedural style returns false on failure.
  
If an invalid Date/Time string is passed, DateMalformedStringException is thrown. Previous to PHP 8.3, this was a warning.
| Version | Description | 
|---|---|
| 8.3.0 | DateTimeImmutable::modify() now throws
       DateMalformedStringException if an
       invalid string is passed.  Previously, it returned false,
       and a warning was emitted. | 
Example #1 DateTimeImmutable::modify() example
Object-oriented style
<?php
$date = new DateTimeImmutable('2006-12-12');
$newDate = $date->modify('+1 day');
echo $newDate->format('Y-m-d');The above example will output:
2006-12-13
Example #2 Beware when adding or subtracting months
<?php
$date = new DateTimeImmutable('2000-12-31');
$newDate1 = $date->modify('+1 month');
echo $newDate1->format('Y-m-d') . "\n";
$newDate2 = $newDate1->modify('+1 month');
echo $newDate2->format('Y-m-d') . "\n";The above example will output:
2001-01-31 2001-03-03
