MongoDB provides the NOW system variable that allows you to get the current datetime value when using an aggregation pipeline.
This can be useful for when you want to update a document with the current datetime.
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MongoDB $dateFromParts
In MongoDB, the $dateFromParts aggregation pipeline operator constructs and returns a Date object from the date’s constituent parts.
You provide each date part as a separate field.
You can specify your constituent date fields in ISO week date format if required.
MongoDB $dateToParts
In MongoDB, the $dateToParts aggregation pipeline operator returns the date parts of a given date.
More specifically, it returns a document that contains the constituent parts of a given BSON Date value as individual properties.
MongoDB $dateToString
In MongoDB, the $dateToString aggregation pipeline operator converts a given date object to a string.
The $dateToString operator accepts either a Date, a Timestamp, or an ObjectId.
MongoDB $dateFromString
In MongoDB, the $dateFromString aggregation pipeline operator converts a date/time string to a date object.
MongoDB $month
In MongoDB, the $month aggregation pipeline operator returns the month of a given date as a number between 1 and 12.
When using the $month operator, you can optionally specify a timezone to use for the result.
The $month operator accepts either a date (as either a Date, a Timestamp, or an ObjectId), or a document that specifies the date and timezone to use.
MongoDB $millisecond
In MongoDB, the $millisecond aggregation pipeline operator returns the millisecond portion of a date as an integer between 0 and 999.
You can optionally specify a timezone to use for the result.
The $millisecond operator accepts either a date (as either a Date, a Timestamp, or an ObjectId), or a document that specifies the date and timezone to use.
MongoDB $second
In MongoDB, the $second aggregation pipeline operator returns the second portion of a date as a number between 0 and 59. The value can also be 60 to account for leap seconds whenever applicable.
You can optionally specify a timezone to use for the result.
The $second operator accepts either a date (as either a Date, a Timestamp, or an ObjectId), or a document that specifies the date and timezone to use.
MongoDB $minute
In MongoDB, the $minute aggregation pipeline operator returns the minute portion of a date as a number between 0 and 59.
You can optionally specify a timezone to use for the result.
The $minute operator accepts either a date (as either a Date, a Timestamp, or an ObjectId), or a document that specifies the date and timezone to use.
MongoDB $hour
In MongoDB, the $hour aggregation pipeline operator returns the hour portion of a date as a number between 0 and 23.
You can optionally specify a timezone to use for the result.
The $hour operator accepts either a date (as either a Date, a Timestamp, or an ObjectId), or a document that specifies the date and timezone to use.