Overview

time package in golang defines two ways of adding or subtracting to a time.

• Add function – It is used to add/subtract a duration to time t. Since duration can be represented in hours, minutes, seconds, milliseconds, microseconds and nanoseconds, therefore Add function can be used to add/subtract hours, minutes, seconds, milliseconds, microseconds and nanoseconds from a time. Its signature is

func (t Time) Add(d Duration) Time

• AddDate function – It is used to add/subtract years, months and days to time t. Its signature is

func (t Time) AddDate(years int, months int, days int) Time

Note: Positive values are used to add to time and negative values are used to subtract. Let’s see a working example of Add and Subtract to time.

Add to time

Below code can be used to add to time

package main
import (
"fmt"
"time"
)
func main() {
t := time.Now()
//Add 1 hours
newT := t.Add(time.Hour * 1)
fmt.Printf("Adding 1 hour\n: %s\n", newT)
//Add 15 min
newT = t.Add(time.Minute * 15)
fmt.Printf("Adding 15 minute\n: %s\n", newT)
//Add 10 sec
newT = t.Add(time.Second * 10)
fmt.Printf("Adding 10 sec\n: %s\n", newT)
//Add 100 millisecond
newT = t.Add(time.Millisecond * 10)
fmt.Printf("Adding 100 millisecond\n: %s\n", newT)
//Add 1000 microsecond
newT = t.Add(time.Millisecond * 10)
fmt.Printf("Adding 1000 microsecond\n: %s\n", newT)
//Add 10000 nanosecond
newT = t.Add(time.Nanosecond * 10000)
fmt.Printf("Adding 1000 nanosecond\n: %s\n", newT)
//Add 1 year 2 month 4 day
newT = t.AddDate(1, 2, 4)
fmt.Printf("Adding 1 year 2 month 4 day\n: %s\n", newT)
}

Output

Adding 1 hour:
2023-02-01 02:16:35.893847 +0530 IST m=+3600.000239893
Adding 15 minute:
2023-02-01 01:31:35.893847 +0530 IST m=+900.000239893
Adding 10 sec:
2023-02-01 01:16:45.893847 +0530 IST m=+10.000239893
Adding 100 millisecond:
2023-02-01 01:16:35.903847 +0530 IST m=+0.010239893
Adding 1000 microsecond:
2023-02-01 01:16:35.903847 +0530 IST m=+0.010239893
Adding 1000 nanosecond:
2023-02-01 01:16:35.893857 +0530 IST m=+0.000249893
Adding 1 year 2 month 4 day:
2023-04-05 01:16:35.893847 +0530 IST

Subtract to time

Below code can be used to subtract to time

package main
import (
"fmt"
"time"
)
func main() {
t := time.Now()
//Subtract 1 hours
newT := t.Add(-time.Hour * 1)
fmt.Printf("Subtracting 1 hour:\n %s\n", newT)
//Subtract 15 min
newT = t.Add(-time.Minute * 15)
fmt.Printf("Subtracting 15 minute:\n %s\n", newT)
//Subtract 10 sec
newT = t.Add(-time.Second * 10)
fmt.Printf("Subtracting 10 sec:\n %s\n", newT)
//Subtract 100 millisecond
newT = t.Add(-time.Millisecond * 10)
fmt.Printf("Subtracting 100 millisecond:\n %s\n", newT)
//Subtract 1000 microsecond
newT = t.Add(-time.Millisecond * 10)
fmt.Printf("Subtracting 1000 microsecond:\n %s\n", newT)
//Subtract 10000 nanosecond
newT = t.Add(-time.Nanosecond * 10000)
fmt.Printf("Subtracting 1000 nanosecond:\n %s\n", newT)
//Subtract 1 year 2 month 4 day
newT = t.AddDate(-1, -2, -4)
fmt.Printf("Subtracting 1 year 2 month 4 day:\n %s\n", newT)
}

Output:

Subtracting 1 hour:
2023-02-01 00:18:29.772673 +0530 IST m=-3599.999784391
Subtracting 15 minute:
2023-02-01 01:03:29.772673 +0530 IST m=-899.999784391
Subtracting 10 sec:
2023-02-01 01:18:19.772673 +0530 IST m=-9.999784391
Subtracting 100 millisecond:
2023-02-01 01:18:29.762673 +0530 IST m=-0.009784391
Subtracting 1000 microsecond:
2023-02-01 01:18:29.762673 +0530 IST m=-0.009784391
Subtracting 1000 nanosecond:
2023-02-01 01:18:29.772663 +0530 IST m=+0.000205609
Subtracting 1 year 2 month 4 day:
2018-11-27 01:18:29.772673 +0530 IST