$dateFromParts (aggregation)
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Definition
$dateFromParts
Constructs and returns a Date object given the date's constituent properties.
The
$dateFromParts
expression has the following syntax:{ $dateFromParts : { 'year': <year>, 'month': <month>, 'day': <day>, 'hour': <hour>, 'minute': <minute>, 'second': <second>, 'millisecond': <ms>, 'timezone': <tzExpression> } } You can also specify your constituent date fields in ISO week date format using the following syntax:
{ $dateFromParts : { 'isoWeekYear': <year>, 'isoWeek': <week>, 'isoDayOfWeek': <day>, 'hour': <hour>, 'minute': <minute>, 'second': <second>, 'millisecond': <ms>, 'timezone': <tzExpression> } } The
$dateFromParts
takes a document with the following fields:Important
You cannot combine the use of calendar dates and ISO week date fields when constructing your
$dateFromParts
input document.FieldRequired/OptionalDescriptionyear
Required if not usingisoWeekYear
Calendar year. Can be any expression that evaluates to a number.
Value range:
If the number specified is outside this range,1
-9999
$dateFromParts
errors. Starting in MongoDB 4.4, the lower bound for this value is1
. In previous versions of MongoDB, the lower bound was0
.isoWeekYear
Required if not usingyear
ISO Week Date Year. Can be any expression that evaluates to a number.
Value range:
If the number specified is outside this range,1
-9999
$dateFromParts
errors. Starting in MongoDB 4.4, the lower bound for this value is1
. In previous versions of MongoDB, the lower bound was0
.month
Optional. Can only be used withyear
.Month. Can be any expression that evaluates to a number.
Defaults to
1
.Value range:
If the number specified is outside this range,1
-12
$dateFromParts
incorporates the difference in the date calculation. See Value Range for examples.isoWeek
Optional. Can only be used withisoWeekYear
.Week of year. Can be any expression that evaluates to a number.
Defaults to
1
.Value range:
If the number specified is outside this range,1
-53
$dateFromParts
incorporates the difference in the date calculation. See Value Range for examples.day
Optional. Can only be used withyear
.Day of month. Can be any expression that evaluates to a number.
Defaults to
1
.Value range:
If the number specified is outside this range,1
-31
$dateFromParts
incorporates the difference in the date calculation. See Value Range for examples.isoDayOfWeek
Optional. Can only be used withisoWeekYear
.Day of week (Monday
1
- Sunday7
). Can be any expression that evaluates to a number.Defaults to
1
.Value range:
If the number specified is outside this range,1
-7
$dateFromParts
incorporates the difference in the date calculation. See Value Range for examples.hour
OptionalHour. Can be any expression that evaluates to a number.
Defaults to
0
.Value range:
If the number specified is outside this range,0
-23
$dateFromParts
incorporates the difference in the date calculation. See Value Range for examples.minute
OptionalMinute. Can be any expression that evaluates to a number.
Defaults to
0
.Value range:
0
-59
If the number specified is outside this range,$dateFromParts
incorporates the difference in the date calculation. See Value Range for examples.second
OptionalSecond. Can be any expression that evaluates to a number.
Defaults to
0
.Value range:
If the number specified is outside this range,0
-59
$dateFromParts
incorporates the difference in the date calculation. See Value Range for examples.millisecond
OptionalMillisecond. Can be any expression that evaluates to a number.
Defaults to
0
.Value range:
If the number specified is outside this range,0
-999
$dateFromParts
incorporates the difference in the date calculation. See Value Range for examples.timezone
Optional<timezone>
can be any expression that evaluates to a string whose value is either:an Olson Timezone Identifier, such as
"Europe/London"
or"America/New_York"
, ora UTC offset in the form:
+/-[hh]:[mm]
, e.g."+04:45"
, or+/-[hh][mm]
, e.g."-0530"
, or+/-[hh]
, e.g."+03"
.
For more information on expressions, see Expression Operators.
Behavior
Value Range
Starting in MongoDB 4.4, the supported value range for year
and
isoWeekYear
is 1-9999
. In prior versions of MongoDB, the lower
bound for these values was 0
and the supported value range was
0-9999
.
If the value specified for fields other than year
, isoWeekYear
,
and timezone
is outside the valid range, $dateFromParts
carries or subtracts the difference from other date parts to calculate
the date.
Value is Greater than the Range
Consider the following $dateFromParts
expression where
the month
field value is 14
, which is 2 months greater than the
maximum value of 12 months(or 1 year):
{ $dateFromParts: { 'year' : 2017, 'month' : 14, 'day': 1, 'hour' : 12 } }
The expression calculates the date by increasing the year
by 1
and setting the month
to 2 to return:
ISODate("2018-02-01T12:00:00Z")
Value is Less than the Range
Consider the following $dateFromParts
expression where
the month
field value is 0
, which is 1 month less than the
minimum value of 1 month:
{ $dateFromParts: { 'year' : 2017, 'month' : 0, 'day': 1, 'hour' : 12 } }
The expression calculates the date by decreasing the year
by 1
and setting the month
to 12 to return:
ISODate("2016-12-01T12:00:00Z")
Time Zone
When using an Olson Timezone Identifier in the <timezone>
field, MongoDB applies the DST offset
if applicable for the specified timezone.
For example, consider a sales
collection with the following document:
{ "_id" : 1, "item" : "abc", "price" : 20, "quantity" : 5, "date" : ISODate("2017-05-20T10:24:51.303Z") }
The following aggregation illustrates how MongoDB handles the DST
offset for the Olson Timezone Identifier. The example uses the
$hour
and $minute
operators to return the
corresponding portions of the date
field:
db.sales.aggregate([ { $project: { "nycHour": { $hour: { date: "$date", timezone: "-05:00" } }, "nycMinute": { $minute: { date: "$date", timezone: "-05:00" } }, "gmtHour": { $hour: { date: "$date", timezone: "GMT" } }, "gmtMinute": { $minute: { date: "$date", timezone: "GMT" } }, "nycOlsonHour": { $hour: { date: "$date", timezone: "America/New_York" } }, "nycOlsonMinute": { $minute: { date: "$date", timezone: "America/New_York" } } } }])
The operation returns the following result:
{ "_id": 1, "nycHour" : 5, "nycMinute" : 24, "gmtHour" : 10, "gmtMinute" : 24, "nycOlsonHour" : 6, "nycOlsonMinute" : 24 }
Example
The following aggregation uses $dateFromParts
to
construct three date objects from the provided input fields:
db.sales.aggregate([ { $project: { date: { $dateFromParts: { 'year' : 2017, 'month' : 2, 'day': 8, 'hour' : 12 } }, date_iso: { $dateFromParts: { 'isoWeekYear' : 2017, 'isoWeek' : 6, 'isoDayOfWeek' : 3, 'hour' : 12 } }, date_timezone: { $dateFromParts: { 'year' : 2016, 'month' : 12, 'day' : 31, 'hour' : 23, 'minute' : 46, 'second' : 12, 'timezone' : 'America/New_York' } } } }])
The operation returns the following result:
{ "_id" : 1, "date" : ISODate("2017-02-08T12:00:00Z"), "date_iso" : ISODate("2017-02-08T12:00:00Z"), "date_timezone" : ISODate("2017-01-01T04:46:12Z") }