Shape · Dates and time

Truncate Date/Time

Rounds dates down to the start of a period, such as the first of the month. Handy before grouping by month.

Also known as: Start of month, date floor

How it works

Click Add truncation for each column and pick a unit: Year, Quarter, Month, Week, Day, Hour, Minute, Second, Millisecond or Microsecond. The value is rounded down to the start of that period; a week starts on Monday. A blank output name replaces the column in place, otherwise a new column is appended and a second rule with the same output name gets a _2. Nulls stay null. Group on the truncated column with Aggregate for period totals.

Inputs and outputs

Settings

truncations: [{column, unit, outputColumn?}]

Example

You want monthly revenue from an orders table. Truncate order_date to Month into order_month, then aggregate SUM of amount grouped by order_month.

More in Dates and time

• Extract Date/Time Parts — Pulls parts out of a date into new columns: year, quarter, month, week, day, weekday, hour, a weekend flag and more.
• Date/Time Arithmetic — Adds or subtracts time from a date, or measures the gap between two dates, from seconds to years or working days. For example, due date = order date + 30 days.
• Time of Day — Drops the date from a timestamp and keeps the clock time, so you can compare times across days.
• Make Date from Parts — Combines separate year, month and day columns (and hour, minute, second) into one real date or timestamp.
• Convert Date/Time to Text — Turns a date into text using a pattern, such as 01/03/2024 or Mar 2024. The result is text, so use it for labels and exports, not for date math.
• Convert Serial Date — Converts between numbers and dates: Unix timestamps, Excel serial dates, Julian days or your own starting point. For example, 45292 from Excel becomes 2024-01-01.
• Convert Timezone — Shifts times from one time zone to another, with daylight saving handled. For example, UTC to Europe/Warsaw.