trunc

Truncates a timestamp value to the specified precision. For example, truncating a timestamp down to the hour returns the timestamp corresponding to start of the hour of the original timestamp's hour.

Syntax

trunc( <timestamp_expr>, <unit> )

Arguments

<timestamp_expr>

This argument must evaluate to a timestamp.

<unit> (named)

This argument must be one of the strings listed below:

• hour
• minute
• second
• millisecond
• microsecond
• nanosecond

Returns

The returned value is of timestamp type.

Examples

Truncate a timestamp down to the minute:

SELECT now(), trunc(now(), 'minute');

+-----------------------------+------------------------+
| now()                       | trunc(now(), 'minute') |
+-----------------------------+------------------------+
| 2025-01-24T08:13:39.192704Z | 2025-01-24T08:13:00Z   |
+-----------------------------+------------------------+