Daily DAX : Day 417 STARTOFQUARTER

Power BI DAX: STARTOFQUARTER Function

Syntax

STARTOFQUARTER(<date>)

Description

Returns the first date of the quarter that contains the given date. The result is always a date at midnight (00:00:00) of the first day of that quarter.

Parameters

• <date> – Any expression that returns a date/datetime value (usually a column from a date table)

Return Value

A date representing the first day of the quarter (e.g., 1 January, 1 April, 1 July, or 1 October).

Examples

Input Date	STARTOFQUARTER Result	Quarter
2025-03-15	2025-01-01	Q1 2025
2025-05-20	2025-04-01	Q2 2025
2025-08-10	2025-07-01	Q3 2025
2025-12-31	2025-10-01	Q4 2025

Common Use Cases

1. Quarter-to-Date (QTD) Calculations
   

   QTD Sales = 
   CALCULATE(
       SUM(Sales[Amount]),
       DATESQTD('Date'[Date])   // Internally uses STARTOFQUARTER
   )

2. Comparing Current Quarter vs Previous Quarter
   

   Previous Quarter Sales = 
   CALCULATE(
       SUM(Sales[Amount]),
       DATEADD(STARTOFQUARTER('Date'[Date]), -1, QUARTER)
   )

3. Creating a Quarter Start Column in a Date Table
   

   Quarter Start = STARTOFQUARTER('Date'[Date])

4. Building Dynamic Titles or Filters
   

   Current Quarter Start = STARTOFQUARTER(TODAY())

Tips

• Use with a proper Date table marked as date table in Power BI for best performance.
• Combine with ENDOFQUARTER to get the full range of a quarter.
• Works with any fiscal calendar if your date table already defines quarters correctly.

Related Functions: STARTOFMONTH, STARTOFYEAR, ENDOFQUARTER, DATEADD, DATESQTD