Date.StartOfQuarter

Date

Returns the first day of the quarter containing the given date.

Syntax

Date.StartOfQuarter(dateTime as any) as any

Parameters

Name	Type	Required	Description
`dateTime`	`any`	Yes	A date, datetime, or datetimezone value.

Return Value

any — A date, datetime, or datetimezone value representing the first day of the quarter.

Remarks

Date.StartOfQuarter returns the first day of the calendar quarter (Q1: January 1, Q2: April 1, Q3: July 1, Q4: October 1) that contains the given date, datetime, or datetimezone value. The return type matches the input type. This is useful for period-over-period comparisons, quarter-to-date filters, and grouping data by quarter.

Pair with Date.EndOfQuarter to construct inclusive quarter-range filters: [OrderDate] >= Date.StartOfQuarter(refDate) and [OrderDate] <= Date.EndOfQuarter(refDate). When passed a plain date, the result is also a date (unlike Date.EndOfQuarter, which returns a datetime).

For the current quarter start, use Date.StartOfQuarter(Date.From(DateTime.LocalNow())). To get the start of the prior quarter, apply Date.AddQuarters first: Date.StartOfQuarter(Date.AddQuarters(Date.From(DateTime.LocalNow()), -1)).

Examples

Example 1: Add quarter-start date to the Sales table

Table.AddColumn(
    Table.SelectColumns(
        Table.FirstN(Sales, 5),
        {"OrderID", "OrderDate"}
    ),
    "QuarterStart", each Date.StartOfQuarter([OrderDate]), type date
)

Result

	OrderID	OrderDate	QuarterStart
1	1	1/15/2024	1/1/2024
2	2	1/18/2024	1/1/2024
3	3	2/1/2024	1/1/2024
4	4	2/10/2024	1/1/2024
5	5	3/5/2024	1/1/2024

Example 2: Start of quarter for all four quarters

#table(
    type table [Quarter = text, StartDate = date],
    {
        {"Q1", Date.StartOfQuarter(#date(2024, 2, 15))},
        {"Q2", Date.StartOfQuarter(#date(2024, 5, 20))},
        {"Q3", Date.StartOfQuarter(#date(2024, 8, 15))},
        {"Q4", Date.StartOfQuarter(#date(2024, 11, 1))}
    }
)

Result

	Quarter	StartDate
1	Q1	1/1/2024
2	Q2	4/1/2024
3	Q3	7/1/2024
4	Q4	10/1/2024

Example 3: Filter orders for the current quarter to date

let
    Today = Date.From(DateTime.LocalNow()),
    QuarterStart = Date.StartOfQuarter(Today)
in
    Table.SelectRows(
        Sales,
        each [OrderDate] >= QuarterStart and [OrderDate] <= Today
    )

Applied Steps

The final output — filters the Sales table to rows where OrderDate falls from the start of the current quarter through today.

	OrderID	CustomerName	Product	Category	UnitPrice	Quantity	OrderDate	Region
1	7	Charlie	Gadget B	Gadgets	50	3	4/1/2024	West
2	8	Diana	Widget C	Widgets	15	8	4/15/2024	North

Compatibility

✓ Power BI Desktop✓ Power BI Service✓ Excel Desktop✓ Excel Online✓ Dataflows✓ Fabric Notebooks