DateTimeOffset.ToOffset Method

July 28, 2014

Converts the value of the current DateTimeOffset object to the date and time specified by an offset value.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

public DateTimeOffset ToOffset(
	TimeSpan offset
)

Parameters

offset
Type: System.TimeSpan
The offset to convert the DateTimeOffset value to.

Return Value

Type: System.DateTimeOffset
An object that is equal to the original DateTimeOffset object (that is, their ToUniversalTime methods return identical points in time) but whose Offset property is set to offset.

ExceptionCondition
ArgumentException

The resulting DateTimeOffset object has a DateTime value earlier than MinValue.

-or-

The resulting DateTimeOffset object has a DateTime value later than MaxValue.

ArgumentOutOfRangeException

offset is less than -14 hours.

-or-

offset is greater than 14 hours.

The ToOffset method is an alternative to calling the TimeZoneInfo.ConvertTime(DateTimeOffset, TimeZoneInfo) method. It can be useful for performing simple conversions from one time zone to another when the time zones' offsets from Coordinated Universal Time (UTC) are known. However, because neither the original DateTimeOffset object nor the new DateTimeOffset object returned by the method call are unambiguously related to a particular time zone, the method does not apply any time zone adjustment rules in the conversion.

The following example illustrates how to use the ToOffset method to convert a DateTimeOffset object to a DateTimeOffset object with a different offset.


using System;

public class Example
{
   private static DateTimeOffset sourceTime;

   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      DateTimeOffset targetTime;
      sourceTime = new DateTimeOffset(2007, 9, 1, 9, 30, 0,
                                      new TimeSpan(-5, 0, 0));

      // Convert to same time (return sourceTime unchanged)
      targetTime = sourceTime.ToOffset(new TimeSpan(-5, 0, 0));
      ShowDateAndTimeInfo(outputBlock, targetTime);

      // Convert to UTC (0 offset)
      targetTime = sourceTime.ToOffset(TimeSpan.Zero);
      ShowDateAndTimeInfo(outputBlock, targetTime);

      // Convert to 8 hours behind UTC
      targetTime = sourceTime.ToOffset(new TimeSpan(-8, 0, 0));
      ShowDateAndTimeInfo(outputBlock, targetTime);

      // Convert to 3 hours ahead of UTC
      targetTime = sourceTime.ToOffset(new TimeSpan(3, 0, 0));
      ShowDateAndTimeInfo(outputBlock, targetTime);
   }

   private static void ShowDateAndTimeInfo(System.Windows.Controls.TextBlock outputBlock, DateTimeOffset newTime)
   {
      outputBlock.Text += String.Format("{0} converts to {1}", sourceTime, newTime) + "\n";
      outputBlock.Text += String.Format("{0} and {1} are equal: {2}",
                        sourceTime, newTime, sourceTime.Equals(newTime)) + "\n";
      outputBlock.Text += String.Format("{0} and {1} are identical: {2}",
                        sourceTime, newTime,
                        sourceTime.EqualsExact(newTime)) + "\n";
      outputBlock.Text += "\n";
   }
}
//
// The example displays the following output:
//    9/1/2007 9:30:00 AM -05:00 converts to 9/1/2007 9:30:00 AM -05:00
//    9/1/2007 9:30:00 AM -05:00 and 9/1/2007 9:30:00 AM -05:00 are equal: True
//    9/1/2007 9:30:00 AM -05:00 and 9/1/2007 9:30:00 AM -05:00 are identical: True
//    
//    9/1/2007 9:30:00 AM -05:00 converts to 9/1/2007 2:30:00 PM +00:00
//    9/1/2007 9:30:00 AM -05:00 and 9/1/2007 2:30:00 PM +00:00 are equal: True
//    9/1/2007 9:30:00 AM -05:00 and 9/1/2007 2:30:00 PM +00:00 are identical: False
//    
//    9/1/2007 9:30:00 AM -05:00 converts to 9/1/2007 6:30:00 AM -08:00
//    9/1/2007 9:30:00 AM -05:00 and 9/1/2007 6:30:00 AM -08:00 are equal: True
//    9/1/2007 9:30:00 AM -05:00 and 9/1/2007 6:30:00 AM -08:00 are identical: False
//    
//    9/1/2007 9:30:00 AM -05:00 converts to 9/1/2007 5:30:00 PM +03:00
//    9/1/2007 9:30:00 AM -05:00 and 9/1/2007 5:30:00 PM +03:00 are equal: True
//    9/1/2007 9:30:00 AM -05:00 and 9/1/2007 5:30:00 PM +03:00 are identical: False


Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Windows Phone

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