How to get specific time from next day - go

Question

I want to create a time.Time for an exact point in time the following day (tomorrow). For now I would like to set the hour and minute.
This is the code I use at the moment:
now := time.Now()
tomorrow := time.Date(now.Year(), now.Month(), now.Day(), 15, 0, 0, 0, time.UTC).AddDate(0,0,1)
This will create a Date for today with the exact time (hour and minute) I am looking for and then adds one day to that Date. This works fine.
Example:
Imagine time.Now() is 2009-11-10 23:00:00 +0000 UTC.
The result of the following code would be: 2009-11-10 15:00:00 +0000 UTC
tomorrow := time.Date(now.Year(), now.Month(), now.Day(), 15, 0, 0, 0, time.UTC)
To this date I add one day using AddDate(0, 0, 1). The result is then the desired time the next day: 2009-11-11 15:00:00 +0000 UTC.
See: https://play.golang.org/p/OKR9V1HN50x
Question:
Is there a shorter way to write this code?

Answer 1

Package time
import "time"
The month, day, hour, min, sec, and nsec values may be outside their
usual ranges and will be normalized during the conversion. For
example, October 32 converts to November 1.
This is more efficient. It minimizes calls to package time functions and methods.
package main
import (
"fmt"
"time"
)
func main() {
now := time.Now()
fmt.Println(now.Round(0))
yyyy, mm, dd := now.Date()
tomorrow := time.Date(yyyy, mm, dd+1, 15, 0, 0, 0, now.Location())
fmt.Println(tomorrow)
}
Output:
2019-06-21 16:23:06.525478162 -0400 EDT
2019-06-22 15:00:00 -0400 EDT
Some benchmarks:
BenchmarkNow-8 31197811 36.6 ns/op
BenchmarkTomorrowPeterSO-8 29852671 38.4 ns/op
BenchmarkTomorrowJens-8 9523422 124 ns/op
bench_test.go:
package main
import (
"testing"
"time"
)
func BenchmarkNow(b *testing.B) {
for N := 0; N < b.N; N++ {
now := time.Now()
_ = now
}
}
var now = time.Now()
func BenchmarkTomorrowPeterSO(b *testing.B) {
for N := 0; N < b.N; N++ {
// now := time.Now()
yyyy, mm, dd := now.Date()
tomorrow := time.Date(yyyy, mm, dd+1, 15, 0, 0, 0, now.Location())
_ = tomorrow
}
}
func BenchmarkTomorrowJens(b *testing.B) {
for N := 0; N < b.N; N++ {
// now := time.Now()
tomorrow := time.Date(now.Year(), now.Month(), now.Day(), 15, 0, 0, 0, now.Location()).AddDate(0, 0, 1)
_ = tomorrow
}
}