Set the ISO date to the 5th week in 2013:
The date_isodate_set() function sets a date according to the ISO 8601 standard, using weeks and day offsets (instead of using a specific date).
|object||Required. Specifies a DateTime object returned by date_create()|
|year||Required. Specifies the year of the date|
|week||Required. Specifies the week of the date|
|day||Optional. Specifies the offset from the first day of the week. Default is 1|
|Return Value:||Returns a DateTime object on success. FALSE on failure|
|Changelog:||PHP 5.3.0: Changed the return value from NULL to DateTime|