docs-v2/content/flux/v0.x/stdlib/date/truncate.md

title	description	aliases	menu	weight	related	introduced
date.truncate() function	The `date.truncate()` function truncates a time to a specified unit.	/influxdb/v2.0/reference/flux/functions/date/truncate/ /influxdb/v2.0/reference/flux/stdlib/date/truncate/ /influxdb/cloud/reference/flux/stdlib/date/truncate/	flux_0_x_ref name parent date.truncate date	301	/flux/v0.x/stdlib/universe/today/	0.37.0

The date.truncate() function truncates a time to a specified unit.

import "date"

date.truncate(
  t: 2019-07-17T12:05:21.012Z,
  unit: 1s
)

// Returns 2019-07-17T12:05:21.000000000Z

{{% note %}}

Truncate to weeks

When truncating a time value to the week (1w), weeks are determined using the Unix epoch (1970-01-01T00:00:00Z UTC). The Unix epoch was on a Thursday, so all calculated weeks begin on Thursday. {{% /note %}}

Parameters

t

The time to operate on. Use an absolute time, relative duration, or integer. Durations are relative to now().

unit

The unit of time to truncate to.

{{% note %}} Only use 1 and the unit of time to specify the unit. For example: 1s, 1m, 1h. {{% /note %}}

Examples

Truncate time values

import "date"

date.truncate(t: 2019-06-03T13:59:01.000000000Z, unit: 1s)
// Returns 2019-06-03T13:59:01.000000000Z

date.truncate(t: 2019-06-03T13:59:01.000000000Z, unit: 1m)
// Returns 2019-06-03T13:59:00.000000000Z

date.truncate(t: 2019-06-03T13:59:01.000000000Z, unit: 1h)
// Returns 2019-06-03T13:00:00.000000000Z

Truncate time values using durations

import "date"

option now = () => 2020-01-01T00:00:30.500000000Z

date.truncate(t: -30s, unit: 1s)
// Returns 2019-12-31T23:59:30.000000000Z

date.truncate(t: -1m, unit: 1m)
// Returns 2019-12-31T23:59:00.000000000Z

date.truncate(t: -1h, unit: 1h)
// Returns 2019-12-31T23:00:00.000000000Z