Date()

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Date()

Returns a date either as a string or as a Date object.

  • Date() returns the current date as a string in the mongo shell.
  • new Date() returns the current date as a Date object. The mongo shell wraps the Date object with the ISODate helper. The ISODate is in UTC.

You can specify a particular date by passing an ISO-8601 date string with a year within the inclusive range 0 through 9999 to the new Date() constructor or the ISODate() function. These functions accept the following formats:

  • new Date("<YYYY-mm-dd>") returns the ISODate with the specified date.
  • new Date("<YYYY-mm-ddTHH:MM:ss>") specifies the datetime in the client’s local timezone and returns the ISODate with the specified datetime in UTC.
  • new Date("<YYYY-mm-ddTHH:MM:ssZ>") specifies the datetime in UTC and returns the ISODate with the specified datetime in UTC.
  • new Date(<integer>) specifies the datetime as milliseconds since the Unix epoch (Jan 1, 1970), and returns the resulting ISODate instance.

Behavior行为

Internally, Date objects are stored as a signed 64-bit integer representing the number of milliseconds since the Unix epoch (Jan 1, 1970).

Not all database operations and drivers support the full 64-bit range. You may safely work with dates with years within the inclusive range 0 through 9999.

Examples示例

Use Date in a Query

If no document with _id equal to 1 exists in the products collection, the following operation inserts a document with the field dateAdded set to the current date:

db.products.update(
   { _id: 1 },
   {
     $set: { item: "apple" },
     $setOnInsert: { dateAdded: new Date() }
   },
   { upsert: true }
)

See also参阅

Return Date as a String

To return the date as a string, use the Date() method, as in the following example:

var myDateString = Date();

Return Date as Date Object

The mongo shell wrap objects of Date type with the ISODate helper; however, the objects remain of type Date.

The following example uses new Date() to return Date object with the specified UTC datetime.

var myDate = new Date("2016-05-18T16:00:00Z");

See also参阅

BSON Date, mongo Shell Date