Parse nodeJs Date.toString() output as time in go

I have a go service which receives data from an external service.

The data looks as follows (json)-

{
  "firstName": "XYZ",
  "lastName": "ABC",
  "createdAtTimestamp": "Mon Nov 21 2022 17:01:59 GMT+0530 (India Standard Time)"
}

Note that createdAtTimestamp is the output in format of nodeJS new Date().toString() which does not have any particular RFC format specified.

How do I parse createdAtTimestamp to time in go ?

I tried this but it is failing-

data, _ := time.Parse(time.RFC1123, "Mon Nov 21 2022 17:01:59 GMT+0530 (India Standard Time)")
	fmt.Println(data.Format(time.RFC3339))

You see time.RFC1123 in the docs https://pkg.go.dev/time, it does not actually match your format. https://pkg.go.dev/time#pkg-constants.

If you know the format of the createdAtTimestamp then first you have to define a layout with the format.

solution at go.dev

package main

import (
	"fmt"
	"time"
)

func main() {
	// The date and time string you want to parse
	createdAtTimestamp := "Mon Nov 21 2022 17:01:59 GMT+0530 (India Standard Time)"

	// The format of the date and time string
	layout := "Mon Jan 02 2006 15:04:05 MST-0700 (India Standard Time)"

	// Parse the date and time string
	parsedTime, err := time.Parse(layout, createdAtTimestamp)
	if err != nil {
		fmt.Println(err)
		return
	}

	// Print the parsed time in RFC3339 format
	fmt.Println(parsedTime.Format(time.RFC3339))
}

I think you'll have to strip off (India Standard Time) (unless you know it will be the same each time), but you can do

https://go.dev/play/p/rWqO9W3laM2

str := "Mon Nov 21 2022 17:01:59 GMT+0530 (India Standard Time)"
data, err := time.Parse("Mon Jan 02 2006 15:04:05 MST-0700", str[:strings.Index(str, " (")])
fmt.Println(data.Format(time.RFC3339), err)

or, if it will always have (India Standard Time), you could do:

str := "Mon Nov 21 2022 17:01:59 GMT+0530 (India Standard Time)"
data, err := time.Parse("Mon Jan 02 2006 15:04:05 MST-0700 (India Standard Time)", str)
fmt.Println(data.Format(time.RFC3339), err)

You can use below Layout to parse your date:

"Mon Jan 02 2006 15:04:05 MST-0700"

In the lines of:

date := "Mon Nov 21 2022 17:01:59 GMT+0530 (India Standard Time)"
data, err := time.Parse("Mon Jan 02 2006 15:04:05 MST-0700", strings.Split(date, " (")[0])