Fix the computation of total seconds with years and months

pendulum/datetime.py

@@ -754,7 +754,7 @@ def _add_timedelta_(self, delta):
             )
         elif isinstance(delta, pendulum.Duration):
             return self.add(
-                years=delta.years, months=delta.months, seconds=delta.total_seconds()
+                years=delta.years, months=delta.months, seconds=delta._total
             )
 
         return self.add(seconds=delta.total_seconds())
@@ -770,14 +770,7 @@ def _subtract_timedelta(self, delta):
         """
         if isinstance(delta, pendulum.Duration):
             return self.subtract(
-                years=delta.years,
-                months=delta.months,
-                weeks=delta.weeks,
-                days=delta.remaining_days,
-                hours=delta.hours,
-                minutes=delta.minutes,
-                seconds=delta.remaining_seconds,
-                microseconds=delta.microseconds,
+                years=delta.years, months=delta.months, seconds=delta._total
             )
 
         return self.subtract(seconds=delta.total_seconds())

pendulum/duration.py

@@ -66,11 +66,19 @@ def __new__(
             raise ValueError("Float year and months are not supported")
 
         self = timedelta.__new__(
-            cls, days, seconds, microseconds, milliseconds, minutes, hours, weeks
+            cls,
+            days + years * 365 + months * 30,
+            seconds,
+            microseconds,
+            milliseconds,
+            minutes,
+            hours,
+            weeks,
         )
 
         # Intuitive normalization
-        total = self.total_seconds()
+        total = self.total_seconds() - (years * 365 + months * 30) * SECONDS_PER_DAY
+        self._total = total
 
         m = 1
         if total < 0:
@@ -80,7 +88,7 @@ def __new__(
         self._seconds = abs(int(total)) % SECONDS_PER_DAY * m
 
         _days = abs(int(total)) // SECONDS_PER_DAY * m
-        self._days = _days + (years * 365 + months * 30)
+        self._days = _days
         self._remaining_days = abs(_days) % 7 * m
         self._weeks = abs(_days) // 7 * m
         self._months = months
@@ -125,10 +133,6 @@ def months(self):
     def weeks(self):
         return self._weeks
 
-    @property
-    def days(self):
-        return self._days
-
     @property
     def remaining_days(self):
         return self._remaining_days
@@ -320,7 +324,7 @@ def __mul__(self, other):
             return self.__class__(
                 years=self._years * other,
                 months=self._months * other,
-                seconds=self.total_seconds() * other,
+                seconds=self._total * other,
             )
 
         if isinstance(other, float):
@@ -341,9 +345,6 @@ def __floordiv__(self, other):
         if isinstance(other, timedelta):
             return usec // other._to_microseconds()
 
-        # Removing years/months approximation
-        usec -= (self._years * 365 + self._months * 30) * SECONDS_PER_DAY * 1e6
-
         if isinstance(other, int):
             return self.__class__(
                 0,
@@ -361,9 +362,6 @@ def __truediv__(self, other):
         if isinstance(other, timedelta):
             return usec / other._to_microseconds()
 
-        # Removing years/months approximation
-        usec -= (self._years * 365 + self._months * 30) * SECONDS_PER_DAY * 1e6
-
         if isinstance(other, int):
             return self.__class__(
                 0,

tests/duration/test_construct.py

@@ -17,12 +17,14 @@ def test_years():
     pi = pendulum.duration(years=2)
     assert_duration(pi, years=2, weeks=0)
     assert 730 == pi.days
+    assert 63072000 == pi.total_seconds()
 
 
 def test_months():
     pi = pendulum.duration(months=3)
     assert_duration(pi, months=3, weeks=0)
     assert 90 == pi.days
+    assert 7776000 == pi.total_seconds()
 
 
 def test_weeks():