go-durationfmt

go-durationfmt is a Go library that allows you to format durations according to a format string. You can specify years, months, days, hours, minutes, and seconds in the format string.

See the Duration Format section for an explanation of the format string rules.

See the Caveats section before using this library.

Duration Format

The format string format that go-durationfmt uses is similar to that used by Go's fmt package. The % character signifies that the next character is a modifier that specifies a particular duration unit. The following is the full list of modifiers supported by go-durationfmt:

• %y - # of years
• %w - # of weeks
• %d - # of days
• %h - # of hours
• %m - # of minutes
• %s - # of seconds
• %% - print a percent sign

You can place a 0 before the h, m, and s modifiers to zeropad those values to two digits. Zeropadding is undefined for the other modifiers.

Format String Examples

The following examples show how a duration of 42 hours, 4 minutes, and 2 seconds will be formatted with various format strings:

Get

Fetch and build go-durationfmt:

go get github.com/davidscholberg/go-durationfmt

Usage

Here's a simple example for using go-durationfmt:

package main

import (
    "fmt"
    "github.com/davidscholberg/go-durationfmt"
    "time"
)

func main() {
    d := (42 * time.Hour) + (4 * time.Minute) + (2 * time.Second)
    durStr, err := durationfmt.Format(d, "%d days, %h hours")
    if err != nil {
        fmt.Println(err)
    } else {
        fmt.Println(durStr)
    }
}

Caveats

• go-durationfmt assumes that there are 24 hours in a day and 365 days in a year, which is not always the case due to such pesky things as leap years, leap seconds, and daylight savings time. If you need your durations to account for such time jumps, then do not use this library.
• go-durationfmt returns durations as integer values, so any fractional durations are truncated.