Fix: missing highlights due to not interpreting timezones right

test/models/user/highlights_test.rb

@@ -8,6 +8,7 @@ class User::HighlightsTest < ActiveSupport::TestCase
     setup do
       @user = users(:david)
       travel_to 1.week.ago + 2.days
+      Current.session = sessions(:david)
     end
 
     test "generate weekly highlights" do
@@ -32,5 +33,35 @@ class User::HighlightsTest < ActiveSupport::TestCase
         assert_equal new_period_highlights, existing_period_highlights
       end
     end
+
+    test "periods respect user timezone for week boundaries" do
+      @user.settings.update!(timezone_name: "America/New_York")
+
+      # Sunday Jan 7, 2024 at 2am EST (7am UTC) - this is Sunday in NYC
+      sunday_in_nyc = Time.zone.parse("2024-01-07 07:00:00 UTC")
+
+      # Saturday Jan 6, 2024 at 11pm EST (Jan 7 4am UTC) - still Saturday in NYC but Sunday in UTC
+      saturday_in_nyc = Time.zone.parse("2024-01-07 04:00:00 UTC")
+
+      # Event on Saturday evening in NYC (but Sunday in UTC)
+      saturday_event = travel_to(saturday_in_nyc) { cards(:logo).track_event("Saturday event") }
+
+      # Events throughout the week starting Sunday in NYC
+      7.times do |i|
+        travel_to(sunday_in_nyc + i.days) { cards(:logo).track_event("Event #{i}") }
+      end
+
+      wednesday = sunday_in_nyc + 3.days
+
+      # The period should start at Sunday in NYC timezone
+      period_start = wednesday.in_time_zone("America/New_York").beginning_of_week(:sunday)
+      period = PeriodHighlights::Period.new(@user.collections, starts_at: period_start, duration: 1.week)
+
+      # The Saturday event should NOT be included (it's in the previous week in NYC time)
+      assert_not_includes period.events, saturday_event
+
+      # Should include 7 events from the current week
+      assert_equal 7, period.events.count
+    end
   end
 end