How to convert ISO 8601 time in golang?
GoGo Problem Overview
What is the equivalent code in golang for the following shell command ?
date -u +%Y-%m-%dT%T%z
Go Solutions
Solution 1 - Go
package main
import (
"time"
"fmt"
)
func main(){
fmt.Println(time.Now().Format(time.RFC3339))
}
Solution 2 - Go
package main
import (
"fmt"
"time"
)
func main() {
fmt.Println(time.Now().UTC().Format("2006-01-02T15:04:05-0700"))
}
Solution 3 - Go
I had the following spec:
YYYY-MM-DDThh:mm:ss.sssZ
with the final Z being explicitly present in the examples.
Here's how I dealt with it:
- first I found the
time.RFCxxxthat was the closest to my target - I copied its value
- I fiddled with it until I found the expected result
which is
2006-01-02T15:04:05.999Z
Solution 4 - Go
ISO8601 allows for variable levels of granularity. You can have just a year, year+month, year+month+day, add a time portion, and optionally have a timezone portion. Go's built-in time parsing, however, requires you to know ahead-of-time which parts will be included.
The github.com/btubbs/datetime library provides a more flexible parser that can handle all the commonly used ISO8601 formats. See https://github.com/btubbs/datetime
Disclosure: I wrote that library.
Solution 5 - Go
Replacing the sign in the format with a Z triggers the ISO 8601 behavior. Which is exactly time.RFC3339. If you are wanting the string output to end in 'Z' what you need to do is convert to the UTC zone.
package main
import (
"fmt"
"time"
)
func main() {
fmt.Println(time.Now().UTC().Format("2006-01-02T15:04:05Z07:00"))
}
// this is the same format used by RFC3339. just a note on why.