In MongoDB, you can use the $convert aggregation pipeline operator to convert a value to a specified type.
You can convert any valid expression to a double, string, ObjectId, boolean, Date, integer, long, or decimal.
MongoDB
MongoDB Date() Method
In MongoDB, the Date() method returns a date either as a string or as a Date object.
- When you call it as
Date(), it returns the current date as a string in themongoshell. - When you call it as
new Date(), it returns the current date as a Date object.
You can also provide a specific date as an argument to new Date(), so that it uses that date.
MongoDB NOW Aggregation Variable
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.
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 $dateToString Format Specifiers
The following table outlines the format specifiers that can be used with the $dateToString aggregation pipeline operator in MongoDB.
MongoDB $dateFromString
In MongoDB, the $dateFromString aggregation pipeline operator converts a date/time string to a date object.
MongoDB $dateFromString Format Specifiers
The following table outlines the format specifiers that can be used with the $dateFromString aggregation pipeline operator in MongoDB.
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.