Fix for DatePicker displays incorrect date selection when navigating to next month.

src/Controls/tests/TestCases.HostApp/Issues/Issue25943.xaml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Maui.Controls.Sample.Issues.Issue25943"
+             xmlns:controls="clr-namespace:Maui.Controls.Sample.Issues" 
+             x:DataType="controls:_25943MainPageViewModel">
+  <VerticalStackLayout Padding="30,0" Spacing="25">
+    <DatePicker HorizontalOptions="Center" VerticalOptions="Center"  AutomationId="DatePicker" Date="{Binding Date}" MaximumDate="{Binding MaxDate}" MinimumDate="{Binding MinDate}"></DatePicker>
+  </VerticalStackLayout>
+</ContentPage>

src/Controls/tests/TestCases.HostApp/Issues/Issue25943.xaml.cs

@@ -0,0 +1,66 @@
+using System.ComponentModel;
+
+namespace Maui.Controls.Sample.Issues
+{
+	[Issue(IssueTracker.Github, 25943, "[Android] DatePicker Graphical Bug", PlatformAffected.Android)]
+	public partial class Issue25943 : ContentPage
+	{
+		public Issue25943()
+		{
+			BindingContext = new _25943MainPageViewModel();
+			InitializeComponent();
+		}
+    }
+
+    public class _25943MainPageViewModel : INotifyPropertyChanged
+    {
+        private DateTime _date = new DateTime(2024, 1, 1);
+        public DateTime Date
+        {
+            get => _date;
+            set
+            {
+                if (_date != value)
+                {
+                    _date = value;
+                    OnPropertyChanged(nameof(Date));
+                }
+            }
+        }
+
+        private DateTime _maxDate = new DateTime(2024, 2, 29);
+        public DateTime MaxDate
+        {
+            get => _maxDate;
+            set
+            {
+                if (_maxDate != value)
+                {
+                    _maxDate = value;
+                    OnPropertyChanged(nameof(MaxDate));
+                }
+            }
+        }
+
+        private DateTime _minDate = new DateTime(2023, 11, 1);
+        public DateTime MinDate
+        {
+            get => _minDate;
+            set
+            {
+                if (_minDate != value)
+                {
+                    _minDate = value;
+                    OnPropertyChanged(nameof(MinDate));
+                }
+            }
+        }
+
+        public event PropertyChangedEventHandler PropertyChanged;
+
+        protected virtual void OnPropertyChanged(string propertyName)
+        {
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+        }
+    }
+}

src/Controls/tests/TestCases.Shared.Tests/Tests/Issues/Issue25943.cs

@@ -0,0 +1,31 @@
+#if TEST_FAILS_ON_CATALYST && TEST_FAILS_ON_IOS //VerifyScreenShot() is not implemented on Mac, and the DatePicker UI behaves differently on iOS and doesn't have a DatePickerDialog like on other platforms.
+using NUnit.Framework;
+using UITest.Appium;
+using UITest.Core;
+
+namespace Microsoft.Maui.TestCases.Tests.Issues
+{
+    public class Issue25943 : _IssuesUITest
+    {
+        public Issue25943(TestDevice device) : base(device)
+        {
+        }
+
+        public override string Issue => "[Android] DatePicker Graphical Bug";
+
+        [Test]
+        [Category(UITestCategories.DatePicker)]
+        public void DatePickerShouldDisplayProperSelectedDate()
+        {
+            App.WaitForElement("DatePicker");
+            App.Tap("DatePicker");
+#if ANDROID
+            App.Tap(AppiumQuery.ByXPath("//android.widget.ImageButton[@content-desc='Next month']"));
+#elif WINDOWS
+            App.Tap("NextButton");
+#endif
+            VerifyScreenshot();
+        }
+    }
+}
+#endif

src/Core/src/Handlers/DatePicker/DatePickerHandler.Android.cs

@@ -20,7 +20,7 @@ protected override MauiDatePicker CreatePlatformView()
 			var date = VirtualView?.Date;
 
 			if (date != null)
-				_dialog = CreateDatePickerDialog(date.Value.Year, date.Value.Month, date.Value.Day);
+				_dialog = CreateDatePickerDialog(date.Value.Year, date.Value.Month - 1, date.Value.Day);
 
 			return mauiDatePicker;
 		}