From 371cf6d29bdc74c847870b22ab390e5dfa7888f4 Mon Sep 17 00:00:00 2001
From: Brandon W Maister <quodlibetor@gmail.com>
Date: Mon, 2 Sep 2019 14:58:54 -0400
Subject: [PATCH] Adjust timezones after doing Duration addition

The internal, tz-independent timestamp was valid, but since the timezone offset
could change as you add or subtract a second or two you would get
nonsense/nonexistent times when you observed them.

Fixes #318
---
 src/datetime.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/datetime.rs b/src/datetime.rs
index e6a0657..b4881bf 100644
--- a/src/datetime.rs
+++ b/src/datetime.rs
@@ -202,7 +202,8 @@ impl<Tz: TimeZone> DateTime<Tz> {
     #[inline]
     pub fn checked_add_signed(self, rhs: OldDuration) -> Option<DateTime<Tz>> {
         let datetime = try_opt!(self.datetime.checked_add_signed(rhs));
-        Some(DateTime { datetime: datetime, offset: self.offset })
+        let tz = self.timezone();
+        Some(tz.from_utc_datetime(&datetime))
     }
 
     /// Subtracts given `Duration` from the current date and time.
@@ -211,7 +212,8 @@ impl<Tz: TimeZone> DateTime<Tz> {
     #[inline]
     pub fn checked_sub_signed(self, rhs: OldDuration) -> Option<DateTime<Tz>> {
         let datetime = try_opt!(self.datetime.checked_sub_signed(rhs));
-        Some(DateTime { datetime: datetime, offset: self.offset })
+        let tz = self.timezone();
+        Some(tz.from_utc_datetime(&datetime))
     }
 
     /// Subtracts another `DateTime` from the current date and time.