483     pub fn checked_add_signed(self, rhs: OldDuration) -> Option<NaiveDateTime> {  in checked_add_signed()
484         let (time, rhs) = self.time.overflowing_add_signed(rhs);  in checked_add_signed()
487         if rhs <= (-1 << MAX_SECS_BITS) || rhs >= (1 << MAX_SECS_BITS) {  in checked_add_signed()
491         let date = try_opt!(self.date.checked_add_signed(OldDuration::seconds(rhs)));  in checked_add_signed()
565     pub fn checked_sub_signed(self, rhs: OldDuration) -> Option<NaiveDateTime> {  in checked_sub_signed()
566         let (time, rhs) = self.time.overflowing_sub_signed(rhs);  in checked_sub_signed()
569         if rhs <= (-1 << MAX_SECS_BITS) || rhs >= (1 << MAX_SECS_BITS) {  in checked_sub_signed()
573         let date = try_opt!(self.date.checked_sub_signed(OldDuration::seconds(rhs)));  in checked_sub_signed()
621     pub fn signed_duration_since(self, rhs: NaiveDateTime) -> OldDuration {  in signed_duration_since()
622         self.date.signed_duration_since(rhs.date) + self.time.signed_duration_since(rhs.time)  in signed_duration_since()
1255     fn add(self, rhs: OldDuration) -> NaiveDateTime {  in add()
1256         self.checked_add_signed(rhs).expect("`NaiveDateTime + Duration` overflowed")  in add()
1262     fn add_assign(&mut self, rhs: OldDuration) {  in add_assign()
1263         *self = self.add(rhs);  in add_assign()
1325     fn sub(self, rhs: OldDuration) -> NaiveDateTime {  in sub()
1326         self.checked_sub_signed(rhs).expect("`NaiveDateTime - Duration` overflowed")  in sub()
1332     fn sub_assign(&mut self, rhs: OldDuration) {  in sub_assign()
1333         *self = self.sub(rhs);  in sub_assign()
1387     fn sub(self, rhs: NaiveDateTime) -> OldDuration {  in sub()
1388         self.signed_duration_since(rhs)  in sub()
2206         fn check((y,m,d,h,n,s): (i32,u32,u32,u32,u32,u32), rhs: Duration,  in test_datetime_add()
2210             assert_eq!(lhs.checked_add_signed(rhs), sum);  in test_datetime_add()
2211             assert_eq!(lhs.checked_sub_signed(-rhs), sum);  in test_datetime_add()