That is consistent though. Constants take type based on context, so 8 * time.Hour has 8 as a time.Duration.

If you have an int variable hours := 8, you have to cast it before multiplying.

This is also true for simple int and float operations.

  f := 2.0
  3 * f

is valid, but x := 3 would need float64(x)*f to be valid. Same is true for addition etc.