Handle DST for the extra timezones displayed

Prior to this commit, the watchface needed to be recompiled and reinstalled a
few times a year. Which was a bit of a hassle.

Unreliable on the actual days when UTC offset changes, since no attempts are
made at hitting the exact hour. That's good enough for me.

4 files changed, 36 insertions, 7 deletions

diff --git a/LICENSE b/LICENSE
index 37c7f6a..a515fbd 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright (C) 2019 cy384, 2020 cos
+Copyright (C) 2019 cy384, 2020-2022 cos
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
diff --git a/Makefile b/Makefile
index 852367d..51d444e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 DEVICE=vivoactive3
 SDK=3.1.7
-VERSION="0.0.2"
+VERSION="0.0.3"
 OUTPUT=bin/mazarine_$(VERSION).prg
 MONKEY_SDK=~/CONNECTIQ
 CONNIQ=$(MONKEY_SDK)/bin/connectiq
diff --git a/manifest.xml b/manifest.xml
index 5638436..abf2ea2 100644
--- a/manifest.xml
+++ b/manifest.xml
@@ -1,5 +1,5 @@
 <iq:manifest xmlns:iq="http://www.garmin.com/xml/connectiq" version="3">
-    <iq:application entry="MazarineApp" id="b3759b67-2fc3-41ea-8e15-a4b501e223a8" launcherIcon="@Drawables.LauncherIcon" minSdkVersion="1.2.0" name="@Strings.AppName" type="watchface" version="0.0.2">
+    <iq:application entry="MazarineApp" id="b3759b67-2fc3-41ea-8e15-a4b501e223a8" launcherIcon="@Drawables.LauncherIcon" minSdkVersion="1.2.0" name="@Strings.AppName" type="watchface" version="0.0.3">
         <iq:products>
             <iq:product id="approachs60"/>
             <iq:product id="d2bravo"/>
diff --git a/source/MazarineView.mc b/source/MazarineView.mc
index d0c5228..725b5d9 100644
--- a/source/MazarineView.mc
+++ b/source/MazarineView.mc
@@ -1,6 +1,6 @@
 // Mazarine
 //
-// Copyright (C) 2019 cy384, 2020 cos
+// Copyright (C) 2019 cy384, 2020-2022 cos
 // All rights reserved.
 //
 // This software may be modified and distributed under the terms
@@ -133,12 +133,41 @@ class MazarineView extends WatchUi.WatchFace {
     }
 
     function draw_timezones(dc) {
+        var today = Gregorian.info(Time.now(), Time.FORMAT_SHORT);
+        var weekday;
+        weekday = today.day_of_week - 1;
+
+        var past_first_sunday = (today.day - weekday) > 0;
+        var past_second_sunday = (today.day > 7) && (today.day - weekday > 7);
+
         draw_utc_offset(dc);
         draw_timezone(dc, 1, "HK", 8);
         // draw_timezone(dc, 3, "ACDT", 10.5);
-        draw_timezone(dc, 2, "NSW", 11);
-        draw_timezone(dc, 3, "NY", -4);
-        draw_timezone(dc, 4, "CA", -7);
+
+        // https://en.wikipedia.org/wiki/Time_in_Australia
+        //  "first Sunday in October	first Sunday in April"
+        if ((today.month > 4 && today.month < 10) ||
+            (today.month == 4 && past_first_sunday ) ||
+            (today.month == 10 && !past_first_sunday ))
+        {
+            draw_timezone(dc, 2, "NSW", 10);
+        } else {
+            draw_timezone(dc, 2, "NSW", 11);
+        }
+
+        // https://en.wikipedia.org/wiki/Daylight_saving_time_in_the_United_States
+        //  "In the U.S., daylight saving time starts on the second Sunday in
+        //   March and ends on the first Sunday in November"
+        if ((today.month > 3 && today.month < 11) ||
+            (today.month == 3 && past_second_sunday ) ||
+            (today.month == 11 && !past_first_sunday ))
+        {
+            draw_timezone(dc, 3, "NY", -4);
+            draw_timezone(dc, 4, "CA", -7);
+        } else {
+            draw_timezone(dc, 3, "NY", -5);
+            draw_timezone(dc, 4, "CA", -8);
+        }
     }
 
     function draw_utc_offset(dc) {