$isoWeek
Returns the week number of the year in ISO 8601 format, ranging from 1 to 53. The operator accepts a date expression that resolves to a Date, Timestamp, or ObjectId. In ISO 8601, weeks start on Monday and the first week of the year is the week that contains the first Thursday of the year.
Syntax
$isoWeek: <dateExpression>
Parameters
dateExpression
objectrequiredAn expression that resolves to a Date, Timestamp, or ObjectId. If the expression resolves to null or is missing, $isoWeek returns null.
Examples
Get ISO week number for promotion events
This query extracts the ISO week number for promotion event start dates.
Query:
db.stores.aggregate([
{ $match: {"_id": "40d6f4d7-50cd-4929-9a07-0a7a133c2e74"} },
{ $unwind: "$promotionEvents" },
{
$project: {
eventName: "$promotionEvents.eventName",
startDate: {
$dateFromParts: {
year: "$promotionEvents.promotionalDates.startDate.Year",
month: "$promotionEvents.promotionalDates.startDate.Month",
day: "$promotionEvents.promotionalDates.startDate.Day"
}
}
}
},
{
$project: {
eventName: 1,
startDate: 1,
isoWeekNumber: { $isoWeek: "$startDate" },
year: { $year: "$startDate" }
}
}
])
Output:
[
{
"_id": "40d6f4d7-50cd-4929-9a07-0a7a133c2e74",
"eventName": "Massive Markdown Mania",
"startDate": "2023-06-29T00:00:00.000Z",
"isoWeekNumber": 26,
"year": 2023
},
{
"_id": "40d6f4d7-50cd-4929-9a07-0a7a133c2e74",
"eventName": "Fantastic Deal Days",
"startDate": "2023-09-27T00:00:00.000Z",
"isoWeekNumber": 39,
"year": 2023
},
{
"_id": "40d6f4d7-50cd-4929-9a07-0a7a133c2e74",
"eventName": "Discount Delight Days",
"startDate": "2023-12-26T00:00:00.000Z",
"isoWeekNumber": 52,
"year": 2023
},
{
"_id": "40d6f4d7-50cd-4929-9a07-0a7a133c2e74",
"eventName": "Super Sale Spectacular",
"startDate": "2024-03-25T00:00:00.000Z",
"isoWeekNumber": 13,
"year": 2024
},
{
"_id": "40d6f4d7-50cd-4929-9a07-0a7a133c2e74",
"eventName": "Grand Deal Days",
"startDate": "2024-06-23T00:00:00.000Z",
"isoWeekNumber": 25,
"year": 2024
},
{
"_id": "40d6f4d7-50cd-4929-9a07-0a7a133c2e74",
"eventName": "Major Bargain Bash",
"startDate": "2024-09-21T00:00:00.000Z",
"isoWeekNumber": 38,
"year": 2024
}
]