Alters the timestamp

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- Alters the timestamp

# DateTime::modify

# date_modify

(PHP 5 >= 5.2.0, PHP 7, PHP 8)

DateTime::modify -- date_modify — Alters the timestamp

### Description

Object-oriented style

public DateTime::modify(string `$modifier`): DateTime|false

Procedural style

date_modify(DateTime `$object`, string `$modifier`): DateTime|false

Alter the timestamp of a DateTime object by incrementing or decrementing in a format accepted by DateTimeImmutable::__construct().

### Parameters

`object`

  Procedural style only: A DateTime object returned by date_create(). The function modifies this object.

`modifier`

  A date/time string. Valid formats are explained in Date and Time Formats.

### Return Values

Returns the modified DateTime object for method chaining or `false` on failure.

### Errors/Exceptions

Object Orientated API only: If an invalid Date/Time string is passed, DateMalformedStringException is thrown.

### Changelog

Version | Description
--- | ---
8.3.0 | Now throws DateMalformedStringException with DateTime::modify() if an invalid string is passed, instead of a warning. date_modify() has not been changed.

### 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

Example #3 All formats of Date and Time are supported

    <?php$date = new DateTime('2020-12-31');$date->modify('July 1st, 2023');echo $date->format('Y-m-d H:i') . "\n";$date->modify('Monday next week');echo $date->format('Y-m-d H:i') . "\n";$date->modify('17:30');echo $date->format('Y-m-d H:i') . "\n";?>

The above example will output:

    2023-07-01 00:00
    2023-07-03 00:00
    2023-07-03 17:30

### See Also

- strtotime() - Parse about any English textual datetime description into a Unix timestamp
- DateTimeImmutable::modify() - Creates a new object with modified timestamp
- DateTime::add() - Modifies a DateTime object, with added amount of days, months, years, hours, minutes and seconds
- 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