Calendar time zone provider

Ical.Net.Benchmarks/OccurencePerfTests.cs

@@ -40,13 +40,13 @@ public void GetOccurrences()
     public void MultipleEventsWithUntilOccurrencesSearchingByWholeCalendar()
     {
         var searchStart = _calendarFourEvents.Events.First().DtStart!
-            .ToZonedOrDefault(tz)
+            .ToZonedOrDefault(tz, _calendarFourEvents.TimeZoneProvider)
             .LocalDateTime
             .PlusYears(-1)
             .InZoneLeniently(tz);
 
         var searchEnd = _calendarFourEvents.Events.Last().DtStart!
-            .ToZonedOrDefault(tz)
+            .ToZonedOrDefault(tz, _calendarFourEvents.TimeZoneProvider)
             .LocalDateTime
             .PlusYears(1)
             .InZoneLeniently(tz)
@@ -59,13 +59,13 @@ public void MultipleEventsWithUntilOccurrencesSearchingByWholeCalendar()
     public void MultipleEventsWithUntilOccurrences()
     {
         var searchStart = _calendarFourEvents.Events.First().DtStart!
-            .ToZonedOrDefault(tz)
+            .ToZonedOrDefault(tz, _calendarFourEvents.TimeZoneProvider)
             .LocalDateTime
             .PlusYears(-1)
             .InZoneLeniently(tz);
 
         var searchEnd = _calendarFourEvents.Events.Last().DtStart!
-            .ToZonedOrDefault(tz)
+            .ToZonedOrDefault(tz, _calendarFourEvents.TimeZoneProvider)
             .LocalDateTime
             .PlusYears(1)
             .InZoneLeniently(tz)
@@ -80,13 +80,13 @@ public void MultipleEventsWithUntilOccurrences()
     public void MultipleEventsWithUntilOccurrencesEventsAsParallel()
     {
         var searchStart = _calendarFourEvents.Events.First().DtStart!
-            .ToZonedOrDefault(tz)
+            .ToZonedOrDefault(tz, _calendarFourEvents.TimeZoneProvider)
             .LocalDateTime
             .PlusYears(-1)
             .InZoneLeniently(tz);
 
         var searchEnd = _calendarFourEvents.Events.Last().DtStart!
-            .ToZonedOrDefault(tz)
+            .ToZonedOrDefault(tz, _calendarFourEvents.TimeZoneProvider)
             .LocalDateTime
             .PlusYears(1)
             .PlusDays(10)
@@ -195,13 +195,13 @@ public void MultipleEventsWithCountOccurrencesSearchingByWholeCalendar()
     {
         var calendar = GetFourCalendarEventsWithCountRule();
         var searchStart = _calendarFourEvents.Events.First().DtStart!
-            .ToZonedOrDefault(tz)
+            .ToZonedOrDefault(tz, _calendarFourEvents.TimeZoneProvider)
             .LocalDateTime
             .PlusYears(-1)
             .InZoneLeniently(tz);
 
         var searchEnd = _calendarFourEvents.Events.Last().DtStart!
-            .ToZonedOrDefault(tz)
+            .ToZonedOrDefault(tz, _calendarFourEvents.TimeZoneProvider)
             .LocalDateTime
             .PlusYears(1)
             .InZoneLeniently(tz)
@@ -215,13 +215,13 @@ public void MultipleEventsWithCountOccurrences()
     {
         var calendar = GetFourCalendarEventsWithCountRule();
         var searchStart = _calendarFourEvents.Events.First().DtStart!
-             .ToZonedOrDefault(tz)
+             .ToZonedOrDefault(tz, _calendarFourEvents.TimeZoneProvider)
              .LocalDateTime
              .PlusYears(-1)
              .InZoneLeniently(tz);
 
         var searchEnd = _calendarFourEvents.Events.Last().DtStart!
-            .ToZonedOrDefault(tz)
+            .ToZonedOrDefault(tz, _calendarFourEvents.TimeZoneProvider)
             .LocalDateTime
             .PlusYears(1)
             .InZoneLeniently(tz)
@@ -237,13 +237,13 @@ public void MultipleEventsWithCountOccurrencesEventsAsParallel()
     {
         var calendar = GetFourCalendarEventsWithCountRule();
         var searchStart = _calendarFourEvents.Events.First().DtStart!
-            .ToZonedOrDefault(tz)
+            .ToZonedOrDefault(tz, _calendarFourEvents.TimeZoneProvider)
             .LocalDateTime
             .PlusYears(-1)
             .InZoneLeniently(tz);
 
         var searchEnd = _calendarFourEvents.Events.Last().DtStart!
-            .ToZonedOrDefault(tz)
+            .ToZonedOrDefault(tz, _calendarFourEvents.TimeZoneProvider)
             .LocalDateTime
             .PlusYears(1)
             .PlusDays(10)

Ical.Net.Tests/DeserializationTests.cs

@@ -124,8 +124,10 @@ public void Bug2938007()
             Assert.That(evt.End?.HasTime, Is.True);
         }
 
-        var results = evt.GetOccurrences(new LocalDateTime(2010, 1, 17, 0, 0, 0).InZoneLeniently("Asia/Tokyo"))
-            .TakeWhileBefore(new LocalDateTime(2010, 2, 1, 0, 0, 0).InZoneLeniently("Asia/Tokyo").ToInstant());
+        var tz = iCal.TimeZoneProvider["Asia/Tokyo"];
+
+        var results = evt.GetOccurrences(new LocalDateTime(2010, 1, 17, 0, 0, 0).InZoneLeniently(tz))
+            .TakeWhileBefore(new LocalDateTime(2010, 2, 1, 0, 0, 0).InZoneLeniently(tz).ToInstant());
 
         foreach (var o in results)
         {

Ical.Net.Tests/FreeBusyTest.cs

@@ -7,7 +7,6 @@
 using System.Collections.Generic;
 using Ical.Net.CalendarComponents;
 using Ical.Net.DataTypes;
-using Ical.Net.Utility;
 using NodaTime;
 using NUnit.Framework;
 using Duration = Ical.Net.DataTypes.Duration;
@@ -31,8 +30,10 @@ public void GetFreeBusyStatusByDateTime()
         evt.Start = new CalDateTime(2025, 10, 1, 8, 0, 0);
         evt.End = new CalDateTime(2025, 10, 1, 9, 0, 0);
 
+        var tz = cal.TimeZoneProvider["America/New_York"];
+
         var freeBusy = cal.GetFreeBusy(
-            DateUtil.GetZone("America/New_York"),
+            tz,
             new CalDateTime(2025, 10, 1, 0, 0, 0),
             new CalDateTime(2025, 10, 7, 11, 59, 59))!;
 
@@ -60,7 +61,7 @@ public void GetFreeBusyStatusByPeriod()
         evt.End = new CalDateTime(2025, 6, 1, 10, 0, 0);
 
         var freeBusy = cal.GetFreeBusy(
-            DateUtil.GetZone("UTC"),
+            cal.TimeZoneProvider["UTC"],
             new CalDateTime(2025, 6, 1, 0, 0, 0, "UTC"),
             new CalDateTime(2025, 6, 7, 0, 0, 0, "UTC"))!;
 
@@ -106,7 +107,6 @@ public void Contains_Tests()
         var periodWithDuration = new FreeBusyEntry(new(start.InUtc().ToCalDateTime(), Duration.FromHours(1)), FreeBusyStatus.Free);
         using (Assert.EnterMultipleScope())
         {
-            Assert.That(periodWithDuration.Contains(null), Is.False, "Contains should return false for null dt.");
             Assert.That(periodWithDuration.Contains(dtBefore), Is.False, "Contains should return false if dt is before start.");
             Assert.That(periodWithDuration.Contains(dtAtStart), Is.True, "Contains should return true for dt equal to start.");
             Assert.That(periodWithDuration.Contains(dtMid), Is.True, "Contains should return true for dt in the middle.");
@@ -263,7 +263,7 @@ public void CreateFiltersOccurrencesByRequestAttendees()
         {
             Assert.That(freeBusy.Entries, Has.Count.EqualTo(1));
             Assert.That(freeBusy.Entries[0].Status, Is.EqualTo(FreeBusyStatus.Busy));
-            Assert.That(freeBusy.Entries[0].StartTime.ToDateTimeUtc(), Is.EqualTo(busyEvent.Start.ToDateTimeUtc()));
+            Assert.That(freeBusy.Entries[0].StartTime, Is.EqualTo(new CalDateTime(2025, 9, 1, 9, 0, 0, "UTC")));
         }
     }
 

Ical.Net.Tests/MatchTimeZoneTests.cs

@@ -6,6 +6,8 @@
 using System;
 using System.Linq;
 using Ical.Net.DataTypes;
+using NodaTime;
+using NodaTime.TimeZones;
 using NUnit.Framework;
 
 namespace Ical.Net.Tests;
@@ -241,4 +243,107 @@ public void MatchTimeZone_DateOnly()
             Assert.That(occurrences.Count, Is.EqualTo(5));
         }
     }
+
+    [Test, Category("Recurrence")]
+    public void MatchTimeZone_CaseInsensitive_EventEval()
+    {
+        const string ical =
+            """
+            BEGIN:VCALENDAR
+            VERSION:2.0
+            PRODID:-//Example Corp//NONSGML Event//EN
+            BEGIN:VEVENT
+            UID:example1
+            SUMMARY:Event with local time and time zone
+            DTSTART;TZID=America/New_york:20231101T090000
+            RRULE:FREQ=DAILY;UNTIL=20231105T130000Z
+            DTEND;TZID=America/New_york:20231101T100000
+            END:VEVENT
+            END:VCALENDAR
+            """;
+
+        var calendar = Calendar.Load(ical)!;
+        var evt = calendar.Events.First();
+
+        // Throws because the default time zone provider
+        // expects "New_York" instead of "New_york".
+        Assert.Throws<DateTimeZoneNotFoundException>(() =>
+        {
+            var _ = evt.GetOccurrences(new CalDateTime(2023, 11, 01))
+                .TakeWhileBefore(new CalDateTime(2023, 11, 06));
+        });
+
+        // Set the calendar time zone provider to ignore case
+        calendar.TimeZoneProvider = CalendarTimeZoneProviders.TzdbWithAliasesIgnoreCase;
+
+        var occurrences = evt.GetOccurrences(new CalDateTime(2023, 11, 01))
+            .TakeWhileBefore(new CalDateTime(2023, 11, 06))
+            .ToList();
+
+        using (Assert.EnterMultipleScope())
+        {
+            Assert.That(occurrences, Has.Count.EqualTo(4));
+            Assert.That(occurrences[0].Start.Zone.Id, Is.EqualTo("America/New_York"));
+        }
+    }
+
+    [Test, Category("Recurrence")]
+    public void MatchTimeZone_CaseInsensitive_CalendarEval()
+    {
+        const string ical =
+            """
+            BEGIN:VCALENDAR
+            VERSION:2.0
+            PRODID:-//Example Corp//NONSGML Event//EN
+            BEGIN:VEVENT
+            UID:example1
+            SUMMARY:Event with local time and time zone
+            DTSTART;TZID=America/New_york:20231101T090000
+            RRULE:FREQ=DAILY;UNTIL=20231105T130000Z
+            DTEND;TZID=America/New_york:20231101T100000
+            END:VEVENT
+            BEGIN:VEVENT
+            UID:example2
+            SUMMARY:Event with local time and time zone
+            DTSTART;TZID=us-eastern:20231101T100000
+            RRULE:FREQ=DAILY;UNTIL=20231105T130000Z
+            DTEND;TZID=us-eastern:20231101T110000
+            END:VEVENT
+            BEGIN:VEVENT
+            UID:example3
+            SUMMARY:Event with local time and time zone
+            DTSTART;TZID=eastern standard time:20231101T110000
+            RRULE:FREQ=DAILY;UNTIL=20231105T130000Z
+            DTEND;TZID=eastern standard time:20231101T120000
+            END:VEVENT
+            END:VCALENDAR
+            """;
+
+        var calendar = Calendar.Load(ical)!;
+
+        var tz = calendar.TimeZoneProvider.GetZoneOrNull("America/Los_Angeles")!;
+
+        var start = new LocalDate(2023, 11, 1).AtStartOfDayInZone(tz);
+        var end = new LocalDate(2023, 11, 6).AtStartOfDayInZone(tz).ToInstant();
+
+        // Throws because the default time zone provider
+        // expects "New_York" instead of "New_york".
+        Assert.Throws<DateTimeZoneNotFoundException>(() =>
+        {
+            var _ = calendar.GetOccurrences(start).TakeWhileBefore(end);
+        });
+
+        // Set the calendar time zone provider to ignore case
+        calendar.TimeZoneProvider = CalendarTimeZoneProviders.TzdbWithAliasesIgnoreCase;
+
+        var occurrences = calendar.GetOccurrences(start)
+            .TakeWhileBefore(end)
+            .ToList();
+
+        using (Assert.EnterMultipleScope())
+        {
+            Assert.That(occurrences, Has.Count.EqualTo(12));
+            Assert.That(occurrences[0].Start.Zone.Id, Is.EqualTo("America/Los_Angeles"));
+        }
+    }
 }

Ical.Net.Tests/ProgramTest.cs

@@ -1,11 +1,12 @@
-//
+//
 // Copyright ical.net project maintainers and contributors.
 // Licensed under the MIT license.
 //
 
 using System;
 using System.Linq;
 using Ical.Net.DataTypes;
+using NodaTime;
 using NUnit.Framework;
 
 namespace Ical.Net.Tests;
@@ -49,24 +50,26 @@ public void Merge1()
         var evt1 = iCal1.Events.First();
         var evt2 = iCal1.Events.Skip(1).First();
 
+        var tz = iCal1.TimeZoneProvider[_tzid];
+
         // Get occurrences for the first event
         var occurrences = evt1.GetOccurrences(
-            new CalDateTime(1996, 1, 1).ToZonedDateTime(_tzid))
-            .TakeWhileBefore(new CalDateTime(2000, 1, 1).ToZonedDateTime(_tzid).ToInstant()).ToList();
+            new LocalDate(1996, 1, 1).AtStartOfDayInZone(tz))
+            .TakeWhileBefore(new LocalDate(2000, 1, 1).AtStartOfDayInZone(tz).ToInstant()).ToList();
 
-        var dateTimes = new[]
+        var dateTimes = new LocalDate[]
         {
-            new CalDateTime(1997, 9, 10, 9, 0, 0, _tzid).ToZonedDateTime(),
-            new CalDateTime(1997, 9, 11, 9, 0, 0, _tzid).ToZonedDateTime(),
-            new CalDateTime(1997, 9, 12, 9, 0, 0, _tzid).ToZonedDateTime(),
-            new CalDateTime(1997, 9, 13, 9, 0, 0, _tzid).ToZonedDateTime(),
-            new CalDateTime(1997, 9, 14, 9, 0, 0, _tzid).ToZonedDateTime(),
-            new CalDateTime(1997, 9, 15, 9, 0, 0, _tzid).ToZonedDateTime(),
-            new CalDateTime(1999, 3, 10, 9, 0, 0, _tzid).ToZonedDateTime(),
-            new CalDateTime(1999, 3, 11, 9, 0, 0, _tzid).ToZonedDateTime(),
-            new CalDateTime(1999, 3, 12, 9, 0, 0, _tzid).ToZonedDateTime(),
-            new CalDateTime(1999, 3, 13, 9, 0, 0, _tzid).ToZonedDateTime(),
-        };
+            new(1997, 9, 10),
+            new(1997, 9, 11),
+            new(1997, 9, 12),
+            new(1997, 9, 13),
+            new(1997, 9, 14),
+            new(1997, 9, 15),
+            new(1999, 3, 10),
+            new(1999, 3, 11),
+            new(1999, 3, 12),
+            new(1999, 3, 13),
+        }.Select(x => x.At(new LocalTime(9, 0)).InZoneStrictly(tz)).ToArray();
 
         for (var i = 0; i < dateTimes.Length; i++)
         {
@@ -79,30 +82,30 @@ public void Merge1()
 
         // Get occurrences for the 2nd event
         occurrences = evt2.GetOccurrences(
-            new CalDateTime(1996, 1, 1).ToZonedDateTime(_tzid))
-            .TakeWhileBefore(new CalDateTime(1998, 4, 1).ToZonedDateTime(_tzid).ToInstant()).ToList();
+            new LocalDate(1996, 1, 1).AtStartOfDayInZone(tz))
+            .TakeWhileBefore(new LocalDate(1998, 4, 1).AtStartOfDayInZone(tz).ToInstant()).ToList();
 
-        var dateTimes1 = new[]
+        var dateTimes1 = new LocalDate[]
         {
-            new CalDateTime(1997, 9, 2, 9, 0, 0, _tzid),
-            new CalDateTime(1997, 9, 9, 9, 0, 0, _tzid),
-            new CalDateTime(1997, 9, 16, 9, 0, 0, _tzid),
-            new CalDateTime(1997, 9, 23, 9, 0, 0, _tzid),
-            new CalDateTime(1997, 9, 30, 9, 0, 0, _tzid),
-            new CalDateTime(1997, 11, 4, 9, 0, 0, _tzid),
-            new CalDateTime(1997, 11, 11, 9, 0, 0, _tzid),
-            new CalDateTime(1997, 11, 18, 9, 0, 0, _tzid),
-            new CalDateTime(1997, 11, 25, 9, 0, 0, _tzid),
-            new CalDateTime(1998, 1, 6, 9, 0, 0, _tzid),
-            new CalDateTime(1998, 1, 13, 9, 0, 0, _tzid),
-            new CalDateTime(1998, 1, 20, 9, 0, 0, _tzid),
-            new CalDateTime(1998, 1, 27, 9, 0, 0, _tzid),
-            new CalDateTime(1998, 3, 3, 9, 0, 0, _tzid),
-            new CalDateTime(1998, 3, 10, 9, 0, 0, _tzid),
-            new CalDateTime(1998, 3, 17, 9, 0, 0, _tzid),
-            new CalDateTime(1998, 3, 24, 9, 0, 0, _tzid),
-            new CalDateTime(1998, 3, 31, 9, 0, 0, _tzid)
-        }.Select(x => x.ToZonedDateTime()).ToArray();
+            new (1997, 9, 2),
+            new (1997, 9, 9),
+            new (1997, 9, 16),
+            new (1997, 9, 23),
+            new (1997, 9, 30),
+            new (1997, 11, 4),
+            new (1997, 11, 11),
+            new (1997, 11, 18),
+            new (1997, 11, 25),
+            new (1998, 1, 6),
+            new (1998, 1, 13),
+            new (1998, 1, 20),
+            new (1998, 1, 27),
+            new (1998, 3, 3),
+            new (1998, 3, 10),
+            new (1998, 3, 17),
+            new (1998, 3, 24),
+            new (1998, 3, 31)
+        }.Select(x => x.At(new LocalTime(9, 0)).InZoneStrictly(tz)).ToArray();
 
         using (Assert.EnterMultipleScope())
         {

Ical.Net.Tests/RecurrenceIdentifierTests.cs

@@ -103,19 +103,5 @@ public void RecurrenceIdentifierSerializer_LowLevel()
         }
     }
 
-    [TestCase("20250831", RecurrenceRange.ThisInstance, 1)]  // other earlier
-    [TestCase("20250901", RecurrenceRange.ThisInstance, 0)]  // same date, same range
-    [TestCase("20250901", RecurrenceRange.ThisAndFuture, -1)] // same date, higher range
-    [TestCase("20250902", RecurrenceRange.ThisInstance, -1)] // other later
-    [TestCase("20250902", RecurrenceRange.ThisAndFuture, -1)] // other later, higher range
-    public void CompareToTests(string dt, RecurrenceRange range, int expected)
-    {
-        var self = new RecurrenceIdentifier(new CalDateTime("20250901"), RecurrenceRange.ThisInstance);
-        var other = new RecurrenceIdentifier(new CalDateTime(dt), range);
-
-        Assert.That(self.CompareTo(other), Is.EqualTo(expected));
-        Assert.That(self.CompareTo(null), Is.EqualTo(1));
-    }
-
 #pragma warning restore CS0618 // Type or member is obsolete
 }