Fixes behavior for some short timezones.

Author: sdispater

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Change Log
 
+## [Unreleased]
+
+### Fixed
+
+- Fixed behavior of some short timezones (like EST, MST or HST).
+
+
 ## [1.2.2] - 2017-06-15
 
 ### Fixed

pendulum/tz/timezone.py

@@ -187,7 +187,7 @@ def _normalize(self, dt, dst_rule=None):
 
         if dt < begin.time:
             tr = begin
-        elif not dt < end.time:
+        elif dt >= end.time:
             tr = end
         else:
             idx = self._find_transition_index(dt)
@@ -202,7 +202,7 @@ def _normalize(self, dt, dst_rule=None):
 
         tzinfo_index = tr._tzinfo_index
         if tr is begin:
-            if not tr.pre_time < dt:
+            if tr.pre_time >= dt:
                 # Before first transition, so use the default offset.
                 offset = self._tzinfos[self._default_tzinfo_index].offset
                 unix_time = (dt - datetime(1970, 1, 1)).total_seconds() - offset
@@ -212,16 +212,21 @@ def _normalize(self, dt, dst_rule=None):
                     fold
                 )
             else:
-                # tr.pre_time < dt < tr.time
-                # Skipped time
-                if dst_rule == self.TRANSITION_ERROR:
-                    raise NonExistingTime(dt)
-                elif dst_rule == self.PRE_TRANSITION:
-                    # We do not apply the transition
-                    (unix_time,
-                     tzinfo_index) = self._get_previous_transition_time(tr, dt, skipped=True)
+                if begin is end:
+                    # We only have one transition
+                    offset = self._tzinfos[tzinfo_index].offset
+                    unix_time = (dt - datetime(1970, 1, 1)).total_seconds() - offset
                 else:
-                    unix_time = tr.unix_time - (tr.pre_time - dt).total_seconds()
+                    # tr.pre_time < dt < tr.time
+                    # Skipped time
+                    if dst_rule == self.TRANSITION_ERROR:
+                        raise NonExistingTime(dt)
+                    elif dst_rule == self.PRE_TRANSITION:
+                        # We do not apply the transition
+                        (unix_time,
+                         tzinfo_index) = self._get_previous_transition_time(tr, dt, skipped=True)
+                    else:
+                        unix_time = tr.unix_time - (tr.time - dt).total_seconds()
         elif tr is end:
             if tr.pre_time < dt:
                 # After the last transition.

tests/tz_tests/test_timezone.py

@@ -168,6 +168,65 @@ def test_short_timezones(self):
         tz = pendulum.timezone('EET')
         self.assertTrue(len(tz.transitions) > 0)
 
+    def test_short_timezones_should_not_modify_time(self):
+        tz = pendulum.timezone('EST')
+        dt = tz.datetime(2017, 6, 15, 14, 0, 0)
+
+        assert dt.year == 2017
+        assert dt.month == 6
+        assert dt.day == 15
+        assert dt.hour == 14
+        assert dt.minute == 0
+        assert dt.second == 0
+
+        tz = pendulum.timezone('HST')
+        dt = tz.datetime(2017, 6, 15, 14, 0, 0)
+
+        assert dt.year == 2017
+        assert dt.month == 6
+        assert dt.day == 15
+        assert dt.hour == 14
+        assert dt.minute == 0
+        assert dt.second == 0
+
+    def test_after_last_transition(self):
+        tz = pendulum.timezone('Europe/Paris')
+        dt = tz.datetime(2135, 6, 15, 14, 0, 0)
+
+        assert dt.year == 2135
+        assert dt.month == 6
+        assert dt.day == 15
+        assert dt.hour == 14
+        assert dt.minute == 0
+        assert dt.second == 0
+        assert dt.microsecond == 0
+
+    def test_on_last_transition(self):
+        tz = pendulum.timezone('Europe/Paris')
+        dt = datetime(2037, 10, 25, 3, 0, 0)
+        dt = tz.convert(dt, dst_rule=tz.POST_TRANSITION)
+
+        assert dt.year == 2037
+        assert dt.month == 10
+        assert dt.day == 25
+        assert dt.hour == 3
+        assert dt.minute == 0
+        assert dt.second == 0
+        assert dt.microsecond == 0
+        assert dt.utcoffset().total_seconds() == 3600
+
+        dt = datetime(2037, 10, 25, 3, 0, 0)
+        dt = tz.convert(dt, dst_rule=tz.PRE_TRANSITION)
+
+        assert dt.year == 2037
+        assert dt.month == 10
+        assert dt.day == 25
+        assert dt.hour == 3
+        assert dt.minute == 0
+        assert dt.second == 0
+        assert dt.microsecond == 0
+        assert dt.utcoffset().total_seconds() == 7200
+
     def test_convert_fold_attribute_is_honored(self):
         self.skip_if_not_36()