Update `timing.md`.

docs/en/framework/infrastructure/timing.md

@@ -89,6 +89,61 @@ var normalizedDateTime = Clock.Normalize(dateTime)
 
 `DisableDateTimeNormalization` attribute can be used to disable the normalization operation for desired classes or properties.
 
+### DateTime Converter Between UTC and User's Time Zone
+
+#### Convert given UTC to user's time zone.
+
+`DateTime ConvertTo(DateTime dateTime)` and `DateTimeOffset ConvertTo(DateTimeOffset dateTimeOffset)` methods convert given UTC `DateTime` or `DateTimeOffset` to the user's time zone.
+
+> If `SupportsMultipleTimezone` is `false` or `dateTime.Kind` is not `Utc` or these is no timezone setting, it returns the given `DateTime` or `DateTimeOffset` without any changes.
+
+**Example:**
+
+If user's `TimeZone Setting` is `Europe/Istanbul`
+
+````csharp
+// 2025-03-01T05:30:00Z
+var utcTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Utc);
+
+var userTime = Clock.ConvertTo(utcTime);
+
+// Europe/Istanbul has 3 hours difference with UTC. So, the result will be 3 hours later.
+userTime.Kind.ShouldBe(DateTimeKind.Unspecified);
+userTime.ToString("O").ShouldBe("2025-03-01T08:30:00");
+````
+
+````csharp
+// 2025-03-01T05:30:00Z
+var utcTime = new DateTimeOffset(new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Utc), TimeSpan.Zero);
+
+var userTime = Clock.ConvertTo(utcTime);
+
+// Europe/Istanbul has 3 hours difference with UTC. So, the result will be 3 hours later.
+userTime.Offset.ShouldBe(TimeSpan.FromHours(3));
+userTime.ToString("O").ShouldBe("2025-03-01T08:30:00.0000000+03:00");
+````
+
+#### Converts given user's DateTime to UTC
+
+`DateTime ConvertFrom(DateTime dateTime)` method convert given user's `DateTime` to UTC.
+
+> If `SupportsMultipleTimezone` is `false` or `dateTime.Kind` is `Utc` or these is no timezone setting, it returns the given `DateTime` without any changes.
+
+**Example:**
+
+If user's `TimeZone Setting` is `Europe/Istanbul`
+
+````csharp
+// 2025-03-01T05:30:00
+var userTime = new DateTime(2025, 3, 1, 5, 30, 0, DateTimeKind.Unspecified); //Same as Local
+
+var utcTime = Clock.ConvertFrom(userTime);
+
+// Europe/Istanbul has 3 hours difference with UTC. So, the result will be 3 hours earlier.
+utcTime.Kind.ShouldBe(DateTimeKind.Utc);
+utcTime.ToString("O").ShouldBe("2025-03-01T02:30:00.0000000Z");
+````
+
 ### Other IClock Properties
 
 In addition to the `Now`, `IClock` service has the following properties:

framework/src/Volo.Abp.Timing/Volo/Abp/Timing/Clock.cs

@@ -94,19 +94,14 @@ public class Clock : IClock, ITransientDependency
     public DateTime ConvertFrom(DateTime dateTime)
     {
         if (!SupportsMultipleTimezone ||
+            dateTime.Kind == DateTimeKind.Utc ||
             CurrentTimezoneProvider.TimeZone.IsNullOrWhiteSpace())
         {
             return dateTime;
         }
 
         var timezoneInfo = TimezoneProvider.GetTimeZoneInfo(CurrentTimezoneProvider.TimeZone);
-        var targetDateTime = dateTime;
-        if (dateTime.Kind == DateTimeKind.Utc)
-        {
-            return dateTime;
-        }
-
-        targetDateTime = DateTime.SpecifyKind(targetDateTime, DateTimeKind.Unspecified);
-        return TimeZoneInfo.ConvertTimeToUtc(targetDateTime, timezoneInfo);
+        dateTime = DateTime.SpecifyKind(dateTime, DateTimeKind.Unspecified);
+        return TimeZoneInfo.ConvertTimeToUtc(dateTime, timezoneInfo);
     }
 }