How to Format Time in Go: Syntax and Examples

In Go, you format time using the Format method on a time.Time object with a layout string that represents the reference time Mon Jan 2 15:04:05 MST 2006. This layout defines the output format by example, not by format codes.

Syntax

Use the Format method on a time.Time value with a layout string. The layout string must be the exact representation of the reference time Mon Jan 2 15:04:05 MST 2006 in the desired output format.

• timeValue.Format(layout string): formats the time according to the layout.
• The layout uses the reference time's values to specify the format.

go

formattedTime := timeValue.Format("2006-01-02 15:04:05")

Example

This example shows how to get the current time and format it as a string in the format YYYY-MM-DD HH:MM:SS.

go

package main

import (
	"fmt"
	"time"
)

func main() {
	now := time.Now()
	formatted := now.Format("2006-01-02 15:04:05")
	fmt.Println("Current time formatted:", formatted)
}

Output

Current time formatted: 2024-06-15 14:30:45

Common Pitfalls

Many beginners try to use format codes like YYYY or MM like in other languages, but Go requires the exact reference time values.

Also, the layout must be a string literal matching the reference time's values, not a date format pattern.

go

package main

import (
	"fmt"
	"time"
)

func main() {
	now := time.Now()

	// Wrong: using format codes like other languages
	// formattedWrong := now.Format("YYYY-MM-DD HH:mm:ss") // This will output the literal string

	// Right: use Go's reference time layout
	formattedRight := now.Format("2006-01-02 15:04:05")

	fmt.Println("Wrong format (literal):", "YYYY-MM-DD HH:mm:ss")
	fmt.Println("Correct format:", formattedRight)
}

Output

Wrong format (literal): YYYY-MM-DD HH:mm:ss
Correct format: 2024-06-15 14:30:45

Quick Reference

Here are some common layout parts and their meanings based on the reference time:

Layout Part	Meaning	Example Output
2006	Year	2024
01	Month (zero-padded)	06
02	Day (zero-padded)	15
15	Hour (24-hour)	14
03	Hour (12-hour)	02
04	Minute	30
05	Second	45
PM	AM/PM marker	PM
MST	Time zone abbreviation	MST

Key Takeaways

Use the exact reference time "Mon Jan 2 15:04:05 MST 2006" as the layout string to format time in Go.

Do not use common format codes like YYYY or MM; Go uses the reference time's values instead.

The Format method returns a string representing the time in the specified layout.

Remember that the layout string is an example time, not a pattern.

Use the time package's Format method on a time.Time value to get formatted time.