$currentDate

The $currentDate operator sets the value of a field to the current date, either as a Date or a timestamp. This operator is useful for tracking when documents were last modified or for setting creation timestamps.

Syntax

{
  $currentDate: {
    <field1>: <typeSpecification1>,
    <field2>: <typeSpecification2>,
    ...
  }
}

Parameters

Parameter Description
field The name of the field to set to the current date.
typeSpecification Optional. Specifies the type of the date value. Can be true (for Date type) or { $type: "timestamp" } for timestamp type. Default is true (Date).

Examples

Consider this sample document from the stores collection.

{
  "_id": "7954bd5c-9ac2-4c10-bb7a-2b79bd0963c5",
  "name": "Lakeshore Retail | DJ Equipment Stop - Port Cecile",
  "location": {
    "lat": 60.1441,
    "lon": -141.5012
  },
  "staff": {
    "totalStaff": {
      "fullTime": 2,
      "partTime": 0
    }
  },
  "sales": {
    "salesByCategory": [
      {
        "categoryName": "DJ Headphones",
        "totalSales": 35921
      }
    ],
    "fullSales": 3700
  },
  "promotionEvents": [
    {
      "eventName": "Bargain Blitz Days",
      "promotionalDates": {
        "startDate": {
          "Year": 2024,
          "Month": 3,
          "Day": 11
        },
        "endDate": {
          "Year": 2024,
          "Month": 2,
          "Day": 18
        }
      },
      "discounts": [
        {
          "categoryName": "DJ Turntables",
          "discountPercentage": 18
        },
        {
          "categoryName": "DJ Mixers",
          "discountPercentage": 15
        }
      ]
    }
  ],
  "tag": [
    "#ShopLocal",
    "#SeasonalSale",
    "#FreeShipping",
    "#MembershipDeals"
  ],
  "company": "Lakeshore Retail",
  "city": "Port Cecile",
  "lastUpdated": {
    "$date": "2024-12-11T10:21:58.274Z"
  }
}

Example 1: Setting current date

To add a lastUpdated field with the current date to a store document, use the $currentDate operator to create the field with the current date as a Date object.

db.stores.updateOne(
  { "_id": "2cf3f885-9962-4b67-a172-aa9039e9ae2f" },
  {
    $currentDate: {
      "lastUpdated": true
    }
  }
)

This operation returns the following the result.

{
  acknowledged: true,
  insertedId: null,
  matchedCount: 1,
  modifiedCount: 1,
  upsertedCount: 0
}

Example 2: Setting current timestamp

To add both a date field and a timestamp field to track modifications, use the $currentDate operator with a value of true and with a typestamp value.

db.stores.updateOne(
  { "_id": "2cf3f885-9962-4b67-a172-aa9039e9ae2f" },
  {
    $currentDate: {
      "lastModified": true,
      "lastModifiedTimestamp": { $type: "timestamp" }
    }
  }
)

This operation returns the following result

{
  acknowledged: true,
  insertedId: null,
  matchedCount: Long("1"),
  modifiedCount: Long("1"),
  upsertedCount: 0
}

Example 3: Updating nested fields

Set current date for nested fields in the document structure.

db.stores.updateOne(
  { "_id": "2cf3f885-9962-4b67-a172-aa9039e9ae2f" },
  {
    $currentDate: {
      "sales.lastSalesUpdate": true,
      "staff.lastStaffUpdate": { $type: "timestamp" }
    }
  }
)

This operation returns the following result.

[
  {
    "_id": "2cf3f885-9962-4b67-a172-aa9039e9ae2f",
    "name": "First Up Consultants | Bed and Bath Center - South Amir",
    "lastUpdated": ISODate("2025-02-12T10:30:45.123Z"),
    "lastModified": ISODate("2025-02-12T10:30:45.123Z"),
    "lastModifiedTimestamp": Timestamp(1739450445, 1),
    "sales": {
      "totalSales": 37701,
      "lastSalesUpdate": ISODate("2025-02-12T10:30:45.123Z"),
      "salesByCategory": [
        {
          "categoryName": "Mattress Toppers",
          "totalSales": 37701
        }
      ]
    },
    "staff": {
      "totalStaff": {
        "fullTime": 18,
        "partTime": 17
      },
      "lastStaffUpdate": Timestamp(1739450445, 1)
    }
  }
]