1 files changed, 19 insertions, 0 deletions
diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 30985060fd..f840783059 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,3 +1,22 @@
+*   Fix `ActiveSupport::TimeWithZone#in` across DST boundaries.
+
+    Previously calls to `in` were being sent to the non-DST aware
+    method `Time#since` via `method_missing`. It is now aliased to
+    the DST aware `ActiveSupport::TimeWithZone#+` which handles
+    transitions across DST boundaries, e.g:
+
+        Time.zone = "US/Eastern"
+
+        t = Time.zone.local(2016,11,6,1)
+        # => Sun, 06 Nov 2016 01:00:00 EDT -05:00 
+
+        t.in(1.hour)
+        # => Sun, 06 Nov 2016 01:00:00 EST -05:00 
+
+    Fixes #26580.
+
+    *Thomas Balthazar*
+
 *   Remove unused parameter `options = nil` for `#clear` of
     `ActiveSupport::Cache::Strategy::LocalCache::LocalStore` and
     `ActiveSupport::Cache::Strategy::LocalCache`.