# Truncating a Unix timestamp to the hour using Go

## 6 jan 2021 | pattern | golang | development

If you want to truncate a unix timestamp to the hour value, you can do this using the `Truncate`

function:

import ( "time" ) // UnixTruncateToHour returns the timestamp truncated to the hour. func UnixTruncateToHour(unixTime int64) int64 { t := time.Unix(unixTime, 0).UTC() return t.Truncate(time.Hour).UTC().Unix() }

`Truncate`

returns the result of rounding`t`

down to a multiple of`d`

(since the zero time). If`d <= 0`

,`Truncate`

returns`t`

stripped of any monotonic clock reading but otherwise unchanged.

`Truncate`

operates on the time as an absolute duration since the zero time; it does not operate on the presentation form of the time. Thus,`Truncate(Hour)`

may return a time with a non-zero minute, depending on the time's Location.

Be aware that there is also a `Round`

function:

import ( "time" ) // UnixRoundToHour returns the timestamp rounded to the hour. func UnixRoundToHour(unixTime int64) int64 { t := time.Unix(unixTime, 0).UTC() return t.Round(time.Hour).UTC().Unix() }

`Round`

returns the result of rounding`t`

to the nearest multiple of`d`

(since the zero time). The rounding behavior for halfway values is to round up. If`d <= 0`

,`Round`

returns`t`

stripped of any monotonic clock reading but otherwise unchanged.

`Round`

operates on the time as an absolute duration since the zero time; it does not operate on the presentation form of the time. Thus,`Round(Hour)`

may return a time with a non-zero minute, depending on the time's Location.