Search code examples
gotimestampdate-conversion

golang RFC2822 conversion


Is there a library or function in the included libraries that converts an RFC timestamp to Unix time (or another format that I can then format into Unix time?)

For example, I'd like to change this Tue Sep 16 21:58:58 +0000 2014 to a Unix timestamp.


Solution

  • For example,

    package main
    
    import (
        "fmt"
        "time"
    )
    
    func main() {
        s := "Tue Sep 16 21:58:58 +0000 2014"
        const rfc2822 = "Mon Jan 02 15:04:05 -0700 2006"
        t, err := time.Parse(rfc2822, s)
        if err != nil {
            fmt.Println(err)
            return
        }
        u := t.Unix()
        fmt.Println(u)
        f := t.Format(time.UnixDate)
        fmt.Println(f)
    }
    

    Output:

    1410904738
    Tue Sep 16 21:58:58 +0000 2014
    

    References:

    Package time

    RFC2822: 3.3. Date and Time Specification

    NOTE:

    There is a package time format constant named RubyDate; it's a misnomer.

    The Go authors were misled by Go Issue 518 which claimed that Ruby Time.now outputs Tue Jan 12 02:52:59 -0800 2010. However,

    #!/usr/bin/env ruby
    print Time.now
    print "\n"
    

    Output:

    2014-09-20 19:40:32 -0400
    

    Later, the issue was revised to say that Tue Jan 12 02:52:59 -0800 2010 was the date format used by the Twitter API. In the beginning, in the "Fail Whale" days, Twitter used Ruby-on-Rails, which may be why they assumed it was a Ruby date format.

    I didn't use the time.RubyDate constant in my example since it's misleading. A constant named rfc2822 provides better documentation.

    References:

    Go: Issue 518: time.Parse - numeric time zones and spacing

    Diff of format.go revision 0f80c5e80c0e

    Twitter Search is Now 3x Faster