$dateSubtract
The $dateSubtract operator subtracts a specified amount of time from a date.
$dateSubtract
The $dateSubtract operator subtracts a specified time unit from a date. It's useful for calculating past dates or intervals in aggregation pipelines.
Syntax
{
$dateSubtract: {
startDate: <dateExpression>,
unit: "<unit>",
amount: <number>,
timezone: "<timezone>" // optional
}
}Parameters
| Parameter | Description |
|---|---|
startDate | The date expression to subtract from. |
unit | The time unit to subtract (for example, "day", "hour"). |
amount | The amount of the time unit to subtract. |
timezone | (Optional) Timezone for date calculation. |
Examples
Consider this sample document from the stores collection.
{
"_id": "0fcc0bf0-ed18-4ab8-b558-9848e18058f4",
"name": "First Up Consultants | Beverage Shop - Satterfieldmouth",
"location": {
"lat": -89.2384,
"lon": -46.4012
},
"staff": {
"totalStaff": {
"fullTime": 8,
"partTime": 20
}
},
"sales": {
"totalSales": 75670,
"salesByCategory": [
{
"categoryName": "Wine Accessories",
"totalSales": 34440
},
{
"categoryName": "Bitters",
"totalSales": 39496
},
{
"categoryName": "Rum",
"totalSales": 1734
}
]
},
"promotionEvents": [
{
"eventName": "Unbeatable Bargain Bash",
"promotionalDates": {
"startDate": {
"Year": 2024,
"Month": 6,
"Day": 23
},
"endDate": {
"Year": 2024,
"Month": 7,
"Day": 2
}
},
"discounts": [
{
"categoryName": "Whiskey",
"discountPercentage": 7
},
{
"categoryName": "Bitters",
"discountPercentage": 15
},
{
"categoryName": "Brandy",
"discountPercentage": 8
},
{
"categoryName": "Sports Drinks",
"discountPercentage": 22
},
{
"categoryName": "Vodka",
"discountPercentage": 19
}
]
},
{
"eventName": "Steal of a Deal Days",
"promotionalDates": {
"startDate": {
"Year": 2024,
"Month": 9,
"Day": 21
},
"endDate": {
"Year": 2024,
"Month": 9,
"Day": 29
}
},
"discounts": [
{
"categoryName": "Organic Wine",
"discountPercentage": 19
},
{
"categoryName": "White Wine",
"discountPercentage": 20
},
{
"categoryName": "Sparkling Wine",
"discountPercentage": 19
},
{
"categoryName": "Whiskey",
"discountPercentage": 17
},
{
"categoryName": "Vodka",
"discountPercentage": 23
}
]
}
]
}Example 1: Subtract seven days
This query calculates the date one week before the lastUpdated field. This query uses $dateSubtract to calculate the date exactly seven days before the storeOpeningDate timestamp.
db.stores.aggregate([
{
$match: { _id: "e6410bb3-843d-4fa6-8c70-7472925f6d0a" }
},
{
$project: {
_id: 0,
dateOneWeekAgo: {
$dateSubtract: {
startDate: "$storeOpeningDate",
unit: "day",
amount: 7
}
}
}
}
])This query returns the following result.
[
{
"dateOneWeekAgo": "2024-08-29T11:50:06.549Z"
}
]