Subtracting time.Duration from time in Go

Question

I have a time.Time value obtained from time.Now() and I want to get another time which is exactly 1 month ago.

I know subtracting is possible

Answer 1

You can negate a time.Duration:

then := now.Add(- dur)

You can even compare a time.Duration against 0:

if dur > 0 {
    dur = - dur
}

then := now.Add(dur)

You can see a working example at http://play.golang.org/p/ml7svlL4eW