Add a Happening Now View

app/models/ability.rb

@@ -31,7 +31,7 @@ class Ability
       event.state == 'confirmed'
     end
 
-    can [:show, :events, :app], Schedule do |schedule|
+    can [:show, :events, :happening_now, :app], Schedule do |schedule|
       schedule.program.schedule_public
     end
 

app/models/event.rb

@@ -274,6 +274,14 @@ class Event < ApplicationRecord
     event_schedules.find_by(schedule_id: selected_schedule_id).try(:start_time)
   end
 
+  ##
+  # Returns the start time at which this event is scheduled
+  #
+  def happening_now?
+    event_schedules.find_by(schedule_id: selected_schedule_id).try(:happening_now?)
+  end
+
+
   ##
   # Returns true or false, if the event is already over or not
   #

app/models/event_schedule.rb

@@ -27,15 +27,21 @@ class EventSchedule < ApplicationRecord
 
   delegate :guid, to: :room, prefix: true
 
-  delegate :timezone, to: :event
+  def timezone
+    event.conference.timezone
+  end
 
   ##
-  # True within 1 hour before and after the event.
+  # True within `threshold` before and after the event.
   #
   def happening_now?(threshold=30.minutes)
-    pre_start_time = (start_time - threshold).in_time_zone(timezone)
-    end_time_with_threshold = (end_time + threshold).in_time_zone(timezone)
-    (pre_start_time..end_time_with_threshold).cover?(Time.now.in_time_zone(timezone))
+    in_tz_start = start_time.in_time_zone(timezone)
+    in_tz_end = start_time.in_time_zone(timezone)
+    in_tz_start -= in_tz_start.utc_offset
+    in_tz_end -= in_tz_end.utc_offset
+    begin_range = Time.now - threshold
+    end_range = Time.now + threshold + 1.minute # The range is exclusive.
+    (begin_range..end_range).cover?(in_tz_start) || (begin_range..end_range).cover?(in_tz_end)
   end
 
   def self.withdrawn_or_canceled_event_schedules(schedule_ids)