This article lists the various aggregation pipeline operators that can be used to return individual date parts from a Date object in MongoDB.

Specific Date Parts

The following table lists the operators that are specific to a particular date part.

Operator	Description
$dayOfMonth	Returns the day of the month for a given date as a number between 1 and 31.
$dayOfWeek	Returns the day of the week for a given date as a number between 1 (Sunday) and 7 (Saturday).
$dayOfYear	Returns the day of the year for a given date as a number between 1 and 366 (leap year).
$hour	Returns the hour for a given date as a number between 0 and 23.
$isoDayOfWeek	Returns the weekday number of a given date in ISO 8601 format, ranging from 1 (for Monday) to 7 (for Sunday).
$isoWeek	Returns the week number of a given date in ISO 8601 format, ranging from 1 to 53.
$isoWeekYear	Returns the year number for a given date in ISO 8601 format.
$millisecond	Returns the milliseconds of a given date as a number between 0 and 999.
$minute	Returns the minute for a given date as a number between 0 and 59.
$month	Returns the month for a given date as a number between 1 (January) and 12 (December).
$second	Returns the seconds for a given date as a number between 0 and 60 (leap seconds).
$week	Returns the week number for a given date as a number between 0 (the partial week that precedes the first Sunday of the year) and 53 (leap year).
$year	Returns the year for a given date as a number (e.g. 2021).

More General Operators

The following operators are more general (i.e. you can use them for all date parts).

Operator	Description
$dateToParts	Returns a document containing the constituent parts of a date.
$dateToString	Returns the date as a string. You can use zero or more format specifiers to return specific date parts.