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DateTimeOffset.ToOffset(TimeSpan) Method

Definition

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

public:
 DateTimeOffset ToOffset(TimeSpan offset);
public DateTimeOffset ToOffset (TimeSpan offset);
member this.ToOffset : TimeSpan -> DateTimeOffset
Public Function ToOffset (offset As TimeSpan) As DateTimeOffset

Parameters

offset
TimeSpan

The offset to convert the DateTimeOffset value to.

Returns

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.

Exceptions

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

-or-

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

offset is less than -14 hours.

-or-

offset is greater than 14 hours.

Examples

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 DateTimeOffsetConversion
{
   private static DateTimeOffset sourceTime;

   public static void Main()
   {
      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(targetTime);

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

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

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

   private static void ShowDateAndTimeInfo(DateTimeOffset newTime)
   {
      Console.WriteLine("{0} converts to {1}", sourceTime, newTime);
      Console.WriteLine("{0} and {1} are equal: {2}",
                        sourceTime, newTime, sourceTime.Equals(newTime));
      Console.WriteLine("{0} and {1} are identical: {2}",
                        sourceTime, newTime,
                        sourceTime.EqualsExact(newTime));
      Console.WriteLine();
   }
}
//
// 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
open System

let sourceTime = DateTimeOffset(2007, 9, 1, 9, 30, 0, TimeSpan(-5, 0, 0))

let showDateAndTimeInfo newTime =
    printfn $"{sourceTime} converts to {newTime}"
    printfn $"{sourceTime} and {newTime} are equal: {sourceTime.Equals newTime}"
    printfn $"{sourceTime} and {newTime} are identical: {sourceTime.EqualsExact newTime}\n"

[<EntryPoint>]
let main _ =
    // Convert to same time (return sourceTime unchanged)
    let targetTime = sourceTime.ToOffset(TimeSpan(-5, 0, 0))
    showDateAndTimeInfo targetTime

    // Convert to UTC (0 offset)
    let targetTime = sourceTime.ToOffset TimeSpan.Zero
    showDateAndTimeInfo targetTime

    // Convert to 8 hours behind UTC
    let targetTime = sourceTime.ToOffset(TimeSpan(-8, 0, 0))
    showDateAndTimeInfo targetTime

    // Convert to 3 hours ahead of UTC
    let targetTime = sourceTime.ToOffset(TimeSpan(3, 0, 0))
    showDateAndTimeInfo targetTime

    0

// 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
Module DateTimeOffsetConversion
   Private sourceTime As New DateTimeOffset(#9/1/2007 9:30AM#, _
                                            New TimeSpan(-5, 0, 0))
   
   Public Sub Main()
      Dim targetTime As DateTimeOffset
      
      ' Convert to same time (return sourceTime unchanged)
      targetTime = sourceTime.ToOffset(New TimeSpan(-5, 0, 0))
      ShowDateAndTimeInfo(targetTime)
      
      ' Convert to UTC (0 offset)
      targetTime = sourceTime.ToOffset(TimeSpan.Zero)
      ShowDateAndTimeInfo(targetTime)
      
      ' Convert to 8 hours behind UTC
      targetTime = sourceTime.ToOffset(New TimeSpan(-8, 0, 0))
      ShowDateAndTimeInfo(targetTime)
      
      ' Convert to 3 hours ahead of UTC
      targetTime = sourceTime.ToOffset(New TimeSpan(3, 0, 0))
      ShowDateAndTimeInfo(targetTime)
   End Sub
   
   Private Sub ShowDateAndTimeInfo(newTime As DateTimeOffset)
      Console.WriteLine("{0} converts to {1}", sourceTime, newTime)
      Console.WriteLine("{0} and {1} are equal: {2}", _
                        sourceTime, newTime, sourceTime.Equals(newTime))
      Console.WriteLine("{0} and {1} are identical: {2}", _
                        sourceTime, newTime, _
                        sourceTime.EqualsExact(newTime)) 
      Console.WriteLine()
   End Sub
End Module
'
' 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

Remarks

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.

Applies to