added unit test

Author: Vignesh-SF3580

src/Controls/src/Core/DateTimeTypeConverter.cs

@@ -9,10 +9,10 @@ namespace Microsoft.Maui.Controls;
 internal class DateTimeTypeConverter : TypeConverter
 {
     public override bool CanConvertFrom(ITypeDescriptorContext? context, Type? sourceType)
-        => sourceType == typeof(DateTime) || sourceType == typeof(DateOnly);
+        => sourceType == typeof(DateOnly);
 
     public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
-        => destinationType == typeof(DateTime) || destinationType == typeof(DateOnly);
+        => destinationType == typeof(DateTime);
 
     public override object ConvertFrom(ITypeDescriptorContext? context, CultureInfo? culture, object value)
     {

src/Controls/src/Core/TimeSpanTypeConverter.cs

@@ -9,10 +9,10 @@ namespace Microsoft.Maui.Controls;
 internal class TimeSpanTypeConverter : TypeConverter
 {
     public override bool CanConvertFrom(ITypeDescriptorContext? context, Type? sourceType)
-        => sourceType == typeof(string) || sourceType == typeof(TimeOnly) || sourceType == typeof(TimeSpan);
+        => sourceType == typeof(TimeOnly);
 
     public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
-        => destinationType == typeof(string) || destinationType == typeof(TimeSpan) || destinationType == typeof(TimeOnly);
+        => destinationType == typeof(TimeSpan);
 
     public override object ConvertFrom(ITypeDescriptorContext? context, CultureInfo? culture, object value)
     {

src/Controls/tests/Core.UnitTests/DateOnlyTypeConverterTests.cs

@@ -35,5 +35,24 @@ public void DateTimeToDateOnlyConversion()
 
 		Assert.Equal(expectedDateOnly, actualDateOnly);
 	}
+
+	[Fact]
+	public void DateOnlyToDatePickerBinding()
+	{
+		var datePicker = new DatePicker();
+		var source = new Issue20438DatePickerViewModel
+		{
+			SelectedDate = new DateOnly(2025, 3, 15)
+		};
+		datePicker.BindingContext = source;
+		datePicker.SetBinding(DatePicker.DateProperty, "SelectedDate");
+		var expectedDateTime = new DateTime(2025, 3, 15);
+		Assert.Equal(expectedDateTime, datePicker.Date);
+	}
+
+	public class Issue20438DatePickerViewModel
+	{
+		public DateOnly SelectedDate { get; set; }
+	}
 }
 #endif

src/Controls/tests/Core.UnitTests/TimeOnlyTypeConverterTests.cs

@@ -34,5 +34,24 @@ public void TimeSpanToTimeOnlyConversion()
 
 		Assert.Equal(expectedTimeOnly, actualTimeOnly);
 	}
+
+	[Fact]
+	public void TimeOnlyToTimePickerBinding()
+	{
+		var timePicker = new TimePicker();
+		var source = new Issue20438TimePickerViewModel
+		{
+			SelectedTime = new TimeOnly(14, 30, 0)
+		};
+		timePicker.BindingContext = source;
+		timePicker.SetBinding(TimePicker.TimeProperty, "SelectedTime");
+		var expectedTimeSpan = new TimeSpan(14, 30, 0);
+		Assert.Equal(expectedTimeSpan, timePicker.Time);
+	}
+
+	public class Issue20438TimePickerViewModel
+	{
+		public TimeOnly SelectedTime { get; set; }
+	}
 }
 #endif