Add class duration to time command output

helpers.go

@@ -162,6 +162,10 @@ type NaiveTime struct {
 	Minutes uint
 }
 
+func (nt NaiveTime) Sub(other NaiveTime) time.Duration {
+	return time.Hour*time.Duration(nt.Hours-other.Hours) + time.Minute*time.Duration(nt.Minutes-other.Minutes)
+}
+
 func ParseNaiveTime(integer uint64) NaiveTime {
 	minutes := uint(integer % 100)
 	hours := uint(integer / 100)