Parsing a date string in the Golang

Question

I tried to parse the date string "2014-09-12T11: 45: 26.371Z" in the Golang.

The code

layout := "2014-09-12T11:45:26.371Z" str := "2014-11-12T11:45:26.371Z" t, err := time.Parse(layout , str) 

analysis time "2014-11-12T11: 47: 39.489Z": month out of range

I got this error.

How to parse this date string?

Answer 1

Use the exact layout numbers described here and a nice blog post here .

So:

 layout := "2006-01-02T15:04:05.000Z" str := "2014-11-12T11:45:26.371Z" t, err := time.Parse(layout, str) if err != nil { fmt.Println(err) } fmt.Println(t) 

gives:

 >> 2014-11-12 11:45:26.371 +0000 UTC 

I know. The skill is overwhelming. Also caught me for the first time. Go just does not use the abstract syntax for the datetime components ( YYYY-MM-DD ), but these are exact numbers ( I think the time it was first go Nope, according to this . Does anyone know?).

Answer 2

The layout used is really " 2006-01-02T15:04:05.000Z " described in the RickyA answer . <br> This is not the "time of the first transition", but rather a mnemonic way to remember this layout.
See pkg / time :

Estimated time used in layouts:

 Mon Jan 2 15:04:05 MST 2006 

which is Unix time 1136239445 .
Since MST is GMT-0700, the start of the clock can be considered as

  01/02 03:04:05PM '06 -0700 

(1,2,3,4,5,6,7, if you remember that 1 per month, and 2 per day, which is not so easy for a European, like me, the date format was used for the day month)

As shown in " time.parse: why does the golan not correctly analyze time ? , this layout (using 1,2,3,4,5,6, 7) must be followed exactly.

Answer 3

As an answer, but to save the input "2006-01-02T15:04:05.000Z" for the layout, you can use the RFC3339 package constant .

 str := "2014-11-12T11:45:26.371Z" t, err := time.Parse(time.RFC3339, str) if err != nil { fmt.Println(err) } fmt.Println(t) 

https://play.golang.org/p/Dgu2ZvHwTh

Answer 4

It's pretty late for the party, and actually nothing is said about what has not yet been said in one form or another, mainly from the links above, but I wanted to give a TL summary; DR for those with less attention:

The date and time of the go format string is very important. It's like Go knows which field is what. They are usually 1-9 from left to right as follows:

• January / January / January / January / 01 / _1 (etc.) per month
• 02 / _2 for the day of the month
• 15/03 / _3 / PM / P / pm / p for the hour and meridian (3 pm)
• 04 / _4 minutes
• 05 / _5 per second
• 2006/06 year
• -0700/07: 00 / MST for the time zone
• .999999999 / .000000000, etc. In incomplete seconds (I think the difference is that trailing zeros are removed)
• Monday / Monday is the day of the week (which actually was 01-02-2006),

Therefore, do not write “01-05-15” as the date format if you do not want “Month-Second-Hour”

(... again, this was basically the summary above.)

Answer 5

I suggest using the constant time.RFC3339 from the time package. You can check other constants from the time package. https://golang.org/pkg/time/#pkg-constants

 package main import ( "fmt" "time" ) func main() { fmt.Println("Time parsing"); dateString := "2014-11-12T11:45:26.371Z" time1, err := time.Parse(time.RFC3339,dateString); if err!=nil { fmt.Println("Error while parsing date :", err); } fmt.Println(time1); } 

Answer 6

It may be too late, but it is for people who may stumble upon this problem and may want to use an external package to parse a date string.

I tried to find the libraries and I found this:

https://github.com/araddon/dateparse

Example from README:

 package main import ( "flag" "fmt" "time" "github.com/apcera/termtables" "github.com/araddon/dateparse" ) var examples = []string{ "May 8, 2009 5:57:51 PM", "Mon Jan 2 15:04:05 2006", "Mon Jan 2 15:04:05 MST 2006", "Mon Jan 02 15:04:05 -0700 2006", "Monday, 02-Jan-06 15:04:05 MST", "Mon, 02 Jan 2006 15:04:05 MST", "Tue, 11 Jul 2017 16:28:13 +0200 (CEST)", "Mon, 02 Jan 2006 15:04:05 -0700", "Thu, 4 Jan 2018 17:53:36 +0000", "Mon Aug 10 15:44:11 UTC+0100 2015", "Fri Jul 03 2015 18:04:07 GMT+0100 (GMT Daylight Time)", "12 Feb 2006, 19:17", "12 Feb 2006 19:17", "03 February 2013", "2013-Feb-03", // mm/dd/yy "3/31/2014", "03/31/2014", "08/21/71", "8/1/71", "4/8/2014 22:05", "04/08/2014 22:05", "4/8/14 22:05", "04/2/2014 03:00:51", "8/8/1965 12:00:00 AM", "8/8/1965 01:00:01 PM", "8/8/1965 01:00 PM", "8/8/1965 1:00 PM", "8/8/1965 12:00 AM", "4/02/2014 03:00:51", "03/19/2012 10:11:59", "03/19/2012 10:11:59.3186369", // yyyy/mm/dd "2014/3/31", "2014/03/31", "2014/4/8 22:05", "2014/04/08 22:05", "2014/04/2 03:00:51", "2014/4/02 03:00:51", "2012/03/19 10:11:59", "2012/03/19 10:11:59.3186369", // Chinese "2014年04月08日", // yyyy-mm-ddThh "2006-01-02T15:04:05+0000", "2009-08-12T22:15:09-07:00", "2009-08-12T22:15:09", "2009-08-12T22:15:09Z", // yyyy-mm-dd hh:mm:ss "2014-04-26 17:24:37.3186369", "2012-08-03 18:31:59.257000000", "2014-04-26 17:24:37.123", "2013-04-01 22:43", "2013-04-01 22:43:22", "2014-12-16 06:20:00 UTC", "2014-12-16 06:20:00 GMT", "2014-04-26 05:24:37 PM", "2014-04-26 13:13:43 +0800", "2014-04-26 13:13:44 +09:00", "2012-08-03 18:31:59.257000000 +0000 UTC", "2015-09-30 18:48:56.35272715 +0000 UTC", "2015-02-18 00:12:00 +0000 GMT", "2015-02-18 00:12:00 +0000 UTC", "2017-07-19 03:21:51+00:00", "2014-04-26", "2014-04", "2014", "2014-05-11 08:20:13,787", // mm.dd.yy "3.31.2014", "03.31.2014", "08.21.71", // yyyymmdd and similar "20140601", // unix seconds, ms "1332151919", "1384216367189", } var ( timezone = "" ) func main() { flag.StringVar(&timezone, "timezone", "UTC", "Timezone aka 'America/Los_Angeles' formatted time-zone") flag.Parse() if timezone != "" { // NOTE: This is very, very important to understand // time-parsing in go loc, err := time.LoadLocation(timezone) if err != nil { panic(err.Error()) } time.Local = loc } table := termtables.CreateTable() table.AddHeaders("Input", "Parsed, and Output as %v") for _, dateExample := range examples { t, err := dateparse.ParseLocal(dateExample) if err != nil { panic(err.Error()) } table.AddRow(dateExample, fmt.Sprintf("%v", t)) } fmt.Println(table.Render()) }