From 112b174e5fad5417a0083eca35c75e01751c4858 Mon Sep 17 00:00:00 2001
From: Sylvain <bond.never.die@gmail.com>
Date: Thu, 31 Aug 2017 17:32:04 +0200
Subject: [PATCH] [bug] invalid time for reccurent events after Daylight Saving
 Time change

---
 app/helpers/application_helper.rb | 12 ++++++++++++
 app/models/event.rb               |  3 +++
 2 files changed, 15 insertions(+)

diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index ae40ef803..445acf540 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -80,6 +80,18 @@ module ApplicationHelper
 		nil
 	end
 
+	##
+	# Apply a correction for a future DateTime due to change in Daylight Saving Time (DST) period
+	# @param datetime {DateTime}
+	# Inspired by https://stackoverflow.com/a/12065605
+	##
+	def dst_correction(datetime)
+		datetime = datetime.in_time_zone(Time.zone.tzinfo.name)
+		datetime = datetime - 1.hour if datetime.dst? && !Time.now.dst?
+		datetime = datetime + 1.hour if Time.now.dst? && !datetime.dst?
+		datetime
+	end
+
 
 	private
 	## inspired by gems/actionview-4.2.5/lib/action_view/helpers/translation_helper.rb
diff --git a/app/models/event.rb b/app/models/event.rb
index 4c9e28395..7d0678171 100644
--- a/app/models/event.rb
+++ b/app/models/event.rb
@@ -1,5 +1,6 @@
 class Event < ActiveRecord::Base
   include NotifyWith::NotificationAttachedObject
+  include ApplicationHelper
 
   has_one :event_image, as: :viewable, dependent: :destroy
   accepts_nested_attributes_for :event_image, allow_destroy: true
@@ -87,8 +88,10 @@ class Event < ActiveRecord::Base
       r.events.each do |date|
         days_diff = availability.end_at.day - availability.start_at.day
         start_at = DateTime.new(date.year, date.month, date.day, availability.start_at.hour, availability.start_at.min, availability.start_at.sec, availability.start_at.zone)
+        start_at = dst_correction(start_at)
         end_date = date + days_diff.days
         end_at = DateTime.new(end_date.year, end_date.month, end_date.day, availability.end_at.hour, availability.end_at.min, availability.end_at.sec, availability.end_at.zone)
+        end_at = dst_correction(end_at)
         if event_image
           ei = EventImage.new(attachment: event_image.attachment)
         end