impl Sub<T> for <T> for Date/Time types

src/date.rs

@@ -360,6 +360,15 @@ impl<Tz: TimeZone> Sub<OldDuration> for Date<Tz> {
     }
 }
 
+impl<Tz: TimeZone> Sub<Date<Tz>> for Date<Tz> {
+    type Output = OldDuration;
+
+    #[inline]
+    fn sub(self, rhs: Date<Tz>) -> OldDuration {
+        self.signed_duration_since(rhs)
+    }
+}
+
 impl<Tz: TimeZone> fmt::Debug for Date<Tz> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{:?}{:?}", self.naive_local(), self.offset)

src/datetime.rs

@@ -485,6 +485,15 @@ impl<Tz: TimeZone> Sub<OldDuration> for DateTime<Tz> {
     }
 }
 
+impl<Tz: TimeZone> Sub<DateTime<Tz>> for DateTime<Tz> {
+    type Output = OldDuration;
+
+    #[inline]
+    fn sub(self, rhs: DateTime<Tz>) -> OldDuration {
+        self.signed_duration_since(rhs)
+    }
+}
+
 impl<Tz: TimeZone> fmt::Debug for DateTime<Tz> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "{:?}{:?}", self.naive_local(), self.offset)

src/naive/date.rs

@@ -1378,6 +1378,15 @@ impl Sub<OldDuration> for NaiveDate {
     }
 }
 
+impl Sub<NaiveDate> for NaiveDate {
+    type Output = OldDuration;
+
+    #[inline]
+    fn sub(self, rhs: NaiveDate) -> OldDuration {
+        self.signed_duration_since(rhs)
+    }
+}
+
 impl SubAssign<OldDuration> for NaiveDate {
     #[inline]
     fn sub_assign(&mut self, rhs: OldDuration) {

src/naive/datetime.rs

@@ -1272,6 +1272,15 @@ impl Sub<OldDuration> for NaiveDateTime {
     }
 }
 
+impl Sub<NaiveDateTime> for NaiveDateTime {
+    type Output = OldDuration;
+
+    #[inline]
+    fn sub(self, rhs: NaiveDateTime) -> OldDuration {
+        self.signed_duration_since(rhs)
+    }
+}
+
 impl SubAssign<OldDuration> for NaiveDateTime {
     #[inline]
     fn sub_assign(&mut self, rhs: OldDuration) {

src/naive/time.rs

@@ -1126,6 +1126,15 @@ impl Sub<OldDuration> for NaiveTime {
     }
 }
 
+impl Sub<NaiveTime> for NaiveTime {
+    type Output = OldDuration;
+
+    #[inline]
+    fn sub(self, rhs: NaiveTime) -> OldDuration {
+        self.signed_duration_since(rhs)
+    }
+}
+
 impl SubAssign<OldDuration> for NaiveTime {
     #[inline]
     fn sub_assign(&mut self, rhs: OldDuration) {