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date.truncate() function

content/flux/v0/stdlib/date/truncate.md

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<!------------------------------------------------------------------------------ IMPORTANT: This page was generated from comments in the Flux source code. Any edits made directly to this page will be overwritten the next time the documentation is generated. To make updates to this documentation, update the function comments above the function definition in the Flux source code: https://github.com/influxdata/flux/blob/master/stdlib/date/date.flux#L894-L894 Contributing to Flux: https://github.com/influxdata/flux#contributing Fluxdoc syntax: https://github.com/influxdata/flux/blob/master/docs/fluxdoc.md ------------------------------------------------------------------------------->

date.truncate() returns a time truncated to the specified duration unit.

Function type signature
js
(t: A, unit: duration, ?location: {zone: string, offset: duration}) => time where A: Timeable

{{% caption %}} For more information, see Function type signatures. {{% /caption %}}

Parameters

t

({{< req >}}) Time to operate on.

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

unit

({{< req >}}) Unit of time to truncate to.

Only use 1 and the unit of time to specify the unit. For example: 1s, 1m, 1h.

location

Location used to determine timezone. Default is the location option.

Examples

Truncate time values

js
import "date"
import "timezone"

option location = timezone.location(name: "Europe/Madrid")

date.truncate(t: 2019-06-03T13:59:01Z, unit: 1s)

// Returns 2019-06-03T13:59:01.000000000Z
date.truncate(t: 2019-06-03T13:59:01Z, unit: 1m)

// Returns 2019-06-03T13:59:00.000000000Z
date.truncate(t: 2019-06-03T13:59:01Z, unit: 1h)

// Returns 2019-06-03T13:00:00.000000000Z
date.truncate(t: 2019-06-03T13:59:01Z, unit: 1d)

// Returns 2019-06-02T22:00:00.000000000Z
date.truncate(t: 2019-06-03T13:59:01Z, unit: 1mo)

// Returns 2019-05-31T22:00:00.000000000Z
date.truncate(t: 2019-06-03T13:59:01Z, unit: 1y)// Returns 2018-12-31T23:00:00.000000000Z

Truncate time values using relative durations

js
import "date"

option now = () => 2020-01-01T00:00:30.5Z

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

Query data from this year

js
import "date"

from(bucket: "example-bucket")
    |> range(start: date.truncate(t: now(), unit: 1y))

Query data from this calendar month

js
import "date"

from(bucket: "example-bucket")
    |> range(start: date.truncate(t: now(), unit: 1mo))