Support specifying a different timezone in Interval attribute

derekantrican · Aug 22, 2024 · eaeb690 · eaeb690
1 parent 80b339e
commit eaeb690
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Showing 3 changed files with 40 additions and 3 deletions.
diff --git a/ClockworkFramework.Core/ClockworkFramework.Core.csproj b/ClockworkFramework.Core/ClockworkFramework.Core.csproj
@@ -3,7 +3,7 @@
   <PropertyGroup>
     <TargetFramework>net6.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
-    <Version>6.4.0</Version>
+    <Version>6.5.0</Version>
   </PropertyGroup>
 
   <ItemGroup>

diff --git a/ClockworkFramework.Core/Interval.cs b/ClockworkFramework.Core/Interval.cs
@@ -16,7 +16,7 @@ public class Interval
         //Todo: simplify interval constructors somehow (and therefore: attribute)
         //Todo: allow for "Interval.Once" to only run a task one time after startup
 
-        public Interval(TimeType timeType, int frequency, int hour, int minute)
+        public Interval(TimeType timeType, int frequency, int hour, int minute, string timezone = null)
         {
             if (timeType == TimeType.Week)
             {
@@ -35,6 +35,7 @@ public Interval(TimeType timeType, int frequency, int hour, int minute)
             Frequency = frequency;
             Hour = hour;
             Minute = minute;
+            Timezone = timezone;
         }
 
         public Interval(TimeType timeType, int frequency)
@@ -56,20 +57,22 @@ public Interval(TimeType timeType, int frequency)
             Frequency = frequency;
         }
 
-        public Interval(DayOfWeek dayOfWeek, int frequency, int hour, int minute)
+        public Interval(DayOfWeek dayOfWeek, int frequency, int hour, int minute, string timezone = null)
         {
             TimeType = TimeType.Week;
             DayOfWeek = dayOfWeek;
             Frequency = frequency;
             Hour = hour;
             Minute = minute;
+            Timezone = timezone;
         }
 
         public TimeType TimeType { get; }
         public int Frequency { get; }
         public DayOfWeek DayOfWeek { get; }
         public int Hour { get; }
         public int Minute { get; }
+        public string Timezone { get; }
 
         public TimeSpan CalculateTimeToNext(DateTime fromDateTime)
         {
@@ -130,6 +133,26 @@ public TimeSpan CalculateTimeToNext(DateTime fromDateTime)
                 throw new Exception("Unable to calculate next occurence");
             }
 
+            if (!string.IsNullOrEmpty(Timezone))
+            {
+                try
+                {
+                    //This is a rudimentary first version. Some potential problems that might arise,
+                    //causing this to provide inaccurate results:
+                    // - At the bottom, we attempt to account for DST changes, but by converting timezones,
+                    //   I wouldn't be surprised if there were multiple DST or similar changes in between
+                    // - Etc. (Timezones can be VERY weird. This could fail in a variety of ways)
+
+                    TimeZoneInfo timeZoneInfo = TimeZoneInfo.FindSystemTimeZoneById(Timezone); //I could use https://github.com/mattjohnsonpint/TimeZoneConverter to support IANA timezones
+
+                    next = TimeZoneInfo.ConvertTime(next.Value, timeZoneInfo);
+                }
+                catch (TimeZoneNotFoundException)
+                {
+                    throw new Exception($"Unrecognized timezone '{Timezone}'");
+                }
+            }
+
             //Using UTC converts here gives us the correct TimeSpan even if there is a DST change in between
             return TimeZoneInfo.ConvertTimeToUtc(next.Value) - TimeZoneInfo.ConvertTimeToUtc(fromDateTime);
         }

diff --git a/ClockworkFramework.Core/IntervalAttribute.cs b/ClockworkFramework.Core/IntervalAttribute.cs
@@ -10,14 +10,28 @@ public IntervalAttribute(TimeType timeType, int frequency)
             Interval = new Interval(timeType, frequency);
         }
 
+        //Interval for "run every # (Hour|Day|Month|etc) [at X time]"
         public IntervalAttribute(TimeType timeType, int frequency, int hour, int minute)
         {
             Interval = new Interval(timeType, frequency, hour, minute);
         }
 
+        //Interval for "run every # (Mon|Tues|Wed|etc) [at X time]"
         public IntervalAttribute(DayOfWeek dayOfWeek, int frequency, int hour, int minute)
         {
             Interval = new Interval(dayOfWeek, frequency, hour, minute);
         }
+
+        //Interval for "run every # (Hour|Day|Month|etc) [at X time]" WITH timezone (https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/default-time-zones)
+        public IntervalAttribute(TimeType timeType, int frequency, int hour, int minute, string timezone)
+        {
+            Interval = new Interval(timeType, frequency, hour, minute, timezone);
+        }
+
+        //Interval for "run every # (Mon|Tues|Wed|etc) [at X time]" WITH timezone (https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/default-time-zones)
+        public IntervalAttribute(DayOfWeek dayOfWeek, int frequency, int hour, int minute, string timezone)
+        {
+            Interval = new Interval(dayOfWeek, frequency, hour, minute, timezone);
+        }
     }
 }