How do I get the time one day ago relative to the current?

I need to query my db for events occurred within a single hour.
Therefore, I want to get events between now and then (which is now - 24 hours, or now - 1 full day).

I tried this approach, but it is incorrect -

package main
import (
	"fmt"
	"time"
)
func main() {
	now := time.Now()
	
	// print the time now
	fmt.Println(now)
	
	then := time.Now()
	diff := 24
	diff = diff.Hours()
	then = then.Add(-diff)
	
	// print the time before 24 hours
	fmt.Println(then)
	
	// print the delta between 'now' and 'then'
	fmt.Println(now.Sub(then))
}

How can I make then == 1 full day / 24 hours before now ?

Thanks a lot for your help!!

Use the Duration constants provided in the time package, like time.Hour

diff := 24 * time.Hour
then := time.Now().Add(-diff)

Or if you want the same time on the previous day (which may not be 24 hours earlier, http://play.golang.org/p/B32RbtUuuS)

then := time.Now().AddDate(0, 0, -1)