Time/Date Formatting in Go

admin

4 years ago

If you have worked with time/date formatting in other languages you might have noticed that the other languages use special placeholders for time/date formatting. For eg ruby language uses

%d for day
%Y for year

etc

In Golang date and time format placeholders look like date and time only. Refer to below placeholder table

Type	Placeholder
Day	2 or 02 or _2
Day of Week	Monday or Mon
Month	01 or 1 or Jan or January
Year	2006 or 06
Hour	03 or 3 or 15
Minutes	04 or 4
Seconds	05 or 5
MilliSeconds (ms)	.000 //Trailing zero will be included or .999 //Trailing zero will be omitted
Micro Seconds (μs)	.000000 //Trailing zero will be included or .999999 //Trailing zero will be omitted
Nano Seconds (ns)	.000000000 //Trailing zero will be included or .999999999 //Trailing zero will be omitted
am/pm	PM or pm
Timezone	MST
Timezone offset	Z0700 or Z070000 or Z07 or Z07:00 or Z07:00:00 or -0700 or -070000 or -07 or -07:00 or -07:00:00

It is easy to remember the above placeholders when represented in sequence.

Weekday-Month-Day-Hour-Min-Seconds-Year-Timezone will be Mon-01-02-03-04-05-06–07

Let’s see some time format code examples

package main

import (
    "fmt"
    "time"
)

func main() {
    now := time.Now()
    
    //Format YYYY-MM-DD
    fmt.Printf("YYYY-MM-DD: %s\n", now.Format("2006-01-02"))

    //Format YY-MM-DD
    fmt.Printf("YY-MM-DD: %s\n", now.Format("06-01-02"))

    //Format YYYY-#{MonthName}-DD
    fmt.Printf("YYYY-#{MonthName}-DD: %s\n", now.Format("2006-Jan-02"))

    //Format HH:MM:SS
    fmt.Printf("HH:MM:SS: %s\n", now.Format("03:04:05"))

    //Format HH:MM:SS Millisecond
    fmt.Printf("HH:MM:SS Millisecond: %s\n", now.Format("03:04:05 .999"))

    //Format YYYY-#{MonthName}-DD WeekDay HH:MM:SS
    fmt.Printf("YYYY-#{MonthName}-DD WeekDay HH:MM:SS: %s\n", now.Format("2006-Jan-02 Monday 03:04:05"))

    //Format YYYY-#{MonthName}-DD WeekDay HH:MM:SS PM Timezone TimezoneOffset
    fmt.Printf("YYYY-#{MonthName}-DD WeekDay HH:MM:SS PM Timezone TimezoneOffset: %s\n", now.Format("2006-Jan-02 Monday 03:04:05 PM MST -07:00"))
}

Output:

YYYY-MM-DD: 2020-01-25
YY-MM-DD: 20-01-25
YYYY-#{MonthName}-DD: 2020-Jan-25
HH:MM:SS: 11:14:16
HH:MM:SS Millisecond: 11:14:16 .213
YYYY-#{MonthName}-DD WeekDay HH:MM:SS: 2020-Jan-25 Saturday 11:14:16
YYYY-#{MonthName}-DD WeekDay HH:MM:SS PM Timezone TimezoneOffset: 2020-Jan-25 Saturday 11:14:16 PM IST +05:30