From 9274f5c2634927e417d3f293379603c0b369dec7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Eustace?= <sebastien@eustace.io>
Date: Sat, 4 Jul 2020 23:58:17 +0200
Subject: [PATCH] Fix the computation of total seconds with years and months

---
 pendulum/datetime.py             | 11 ++-------
 pendulum/duration.py             | 42 ++++++++++++++++++++------------
 tests/duration/test_construct.py |  2 ++
 3 files changed, 31 insertions(+), 24 deletions(-)

diff --git a/pendulum/datetime.py b/pendulum/datetime.py
index 610af71e..d79257ca 100644
--- a/pendulum/datetime.py
+++ b/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())
diff --git a/pendulum/duration.py b/pendulum/duration.py
index ff1a91b5..1ad9e19a 100644
--- a/pendulum/duration.py
+++ b/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
@@ -103,10 +111,18 @@ def total_weeks(self):
     if PYPY:
 
         def total_seconds(self):
+            days = 0
+
+            if hasattr(self, "_years"):
+                days += self._years * 365
+
+            if hasattr(self, "_months"):
+                days += self._months * 30
+
             if hasattr(self, "_remaining_days"):
-                days = self._weeks * 7 + self._remaining_days
+                days += self._weeks * 7 + self._remaining_days
             else:
-                days = self._days
+                days += self._days
 
             return (
                 (days * SECONDS_PER_DAY + self._seconds) * US_PER_SECOND
@@ -125,9 +141,11 @@ def months(self):
     def weeks(self):
         return self._weeks
 
-    @property
-    def days(self):
-        return self._days
+    if PYPY:
+
+        @property
+        def days(self) -> int:
+            return self._years * 365 + self._months * 30 + self._days
 
     @property
     def remaining_days(self):
@@ -320,7 +338,7 @@ 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 +359,6 @@ 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 +376,6 @@ 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,
diff --git a/tests/duration/test_construct.py b/tests/duration/test_construct.py
index 8afb1bb3..31ca0ea2 100644
--- a/tests/duration/test_construct.py
+++ b/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():