TimeZoneInfo.GetAmbiguousTimeOffsets Method

Reference

Definition

Namespace:: System

Assembly:: System.Runtime.dll

Assembly:: System.Core.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Important

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Returns information about the possible dates and times that an ambiguous date and time can be mapped to.

Overloads

GetAmbiguousTimeOffsets(DateTime)	Returns information about the possible dates and times that an ambiguous date and time can be mapped to.
GetAmbiguousTimeOffsets(DateTimeOffset)	Returns information about the possible dates and times that an ambiguous date and time can be mapped to.

GetAmbiguousTimeOffsets(DateTime)

Source:: TimeZoneInfo.cs

Source:: TimeZoneInfo.cs

Source:: TimeZoneInfo.cs

Returns information about the possible dates and times that an ambiguous date and time can be mapped to.

public:
 cli::array <TimeSpan> ^ GetAmbiguousTimeOffsets(DateTime dateTime);

public TimeSpan[] GetAmbiguousTimeOffsets (DateTime dateTime);

member this.GetAmbiguousTimeOffsets : DateTime -> TimeSpan[]

Public Function GetAmbiguousTimeOffsets (dateTime As DateTime) As TimeSpan()

Parameters

dateTime: DateTime

A date and time.

Returns

TimeSpan[]

An array of objects that represents possible Coordinated Universal Time (UTC) offsets that a particular date and time can be mapped to.

Exceptions

ArgumentException

dateTime is not an ambiguous time.

Examples

The following example defines a method named ShowPossibleUtcTimes that uses the GetAmbiguousTimeOffsets(DateTime) method to map an ambiguous time to its possible corresponding Coordinated Universal Time (UTC) times.

private void ShowPossibleUtcTimes(DateTime ambiguousTime, TimeZoneInfo timeZone)
{
   // Determine if time is ambiguous in target time zone
   if (!timeZone.IsAmbiguousTime(ambiguousTime))
   {
      Console.WriteLine("{0} is not ambiguous in time zone {1}.", 
                        ambiguousTime, 
                        timeZone.DisplayName);
   }
   else
   {
      // Display time and its time zone (local, UTC, or indicated by timeZone argument)
      string originalTimeZoneName; 
      if (ambiguousTime.Kind == DateTimeKind.Utc)
         originalTimeZoneName = "UTC";
      else if (ambiguousTime.Kind == DateTimeKind.Local)
         originalTimeZoneName = "local time";
      else
         originalTimeZoneName = timeZone.DisplayName;

      Console.WriteLine("{0} {1} maps to the following possible times:", 
                        ambiguousTime, originalTimeZoneName);
      // Get ambiguous offsets 
      TimeSpan[] offsets = timeZone.GetAmbiguousTimeOffsets(ambiguousTime);
      // Handle times not in time zone of timeZone argument
      // Local time where timeZone is not local zone
      if ((ambiguousTime.Kind == DateTimeKind.Local) && ! timeZone.Equals(TimeZoneInfo.Local)) 
         ambiguousTime = TimeZoneInfo.ConvertTime(ambiguousTime, TimeZoneInfo.Local, timeZone);
      // UTC time where timeZone is not UTC zone   
      else if ((ambiguousTime.Kind == DateTimeKind.Utc) && ! timeZone.Equals(TimeZoneInfo.Utc))
         ambiguousTime = TimeZoneInfo.ConvertTime(ambiguousTime, TimeZoneInfo.Utc, timeZone);

      // Display each offset and its mapping to UTC
      foreach (TimeSpan offset in offsets)
      {
         if (offset.Equals(timeZone.BaseUtcOffset))
            Console.WriteLine("If {0} is {1}, {2} UTC", ambiguousTime, timeZone.StandardName, ambiguousTime - offset);
         else
            Console.WriteLine("If {0} is {1}, {2} UTC", ambiguousTime, timeZone.DaylightName, ambiguousTime - offset);
      }
   }            
}

let showPossibleUtcTimes (ambiguousTime: DateTime) (timeZone: TimeZoneInfo) =
    // Determine if time is ambiguous in target time zone
    if not (timeZone.IsAmbiguousTime ambiguousTime) then
        printfn $"{ambiguousTime} is not ambiguous in time zone {timeZone.DisplayName}."
    else
        // Display time and its time zone (local, UTC, or indicated by timeZone argument)
        let originalTimeZoneName =
            match ambiguousTime.Kind with
            | DateTimeKind.Utc -> "UTC"
            | DateTimeKind.Local -> "local time"
            | _ -> timeZone.DisplayName

        printfn $"{ambiguousTime} {originalTimeZoneName} maps to the following possible times:"
        // Get ambiguous offsets 
        let offsets = timeZone.GetAmbiguousTimeOffsets ambiguousTime
        // Handle times not in time zone of timeZone argument
        // Local time where timeZone is not local zone
        let ambiguousTime =
            if (ambiguousTime.Kind = DateTimeKind.Local) && not (timeZone.Equals TimeZoneInfo.Local) then 
                TimeZoneInfo.ConvertTime(ambiguousTime, TimeZoneInfo.Local, timeZone)
            // UTC time where timeZone is not UTC zone   
            elif (ambiguousTime.Kind = DateTimeKind.Utc) && not (timeZone.Equals TimeZoneInfo.Utc) then
                TimeZoneInfo.ConvertTime(ambiguousTime, TimeZoneInfo.Utc, timeZone)
            else 
                ambiguousTime
        // Display each offset and its mapping to UTC
        for offset in offsets do
            if offset.Equals timeZone.BaseUtcOffset then
                printfn $"If {ambiguousTime} is {timeZone.StandardName}, {ambiguousTime - offset} UTC"
            else
                printfn $"If {ambiguousTime} is {timeZone.DaylightName}, {ambiguousTime - offset} UTC"

Private Sub ShowPossibleUtcTimes(ambiguousTime As Date, timeZone As TimeZoneInfo)
   ' Determine if time is ambiguous in target time zone
   If Not timeZone.IsAmbiguousTime(ambiguousTime) Then
      Console.WriteLine("{0} is not ambiguous in time zone {1}.", _
                        ambiguousTime, _
                        timeZone.DisplayName)
   Else
      ' Display time and its time zone (local, UTC, or indicated by timeZone argument)
      Dim originalTimeZoneName As String 
      If ambiguousTime.Kind = DateTimeKind.Utc Then
         originalTimeZoneName = "UTC"
      ElseIf ambiguousTime.Kind = DateTimeKind.Local Then
         originalTimeZoneName = "local time"
      Else
         originalTimeZoneName = timeZone.DisplayName
      End If      
      Console.WriteLine("{0} {1} maps to the following possible times:", _
                        ambiguousTime, originalTimeZoneName)
      ' Get ambiguous offsets 
      Dim offsets() As TimeSpan = timeZone.GetAmbiguousTimeOffsets(ambiguousTime)
      ' Handle times not in time zone of timeZone argument
      ' Local time where timeZone is not local zone
      If (ambiguousTime.Kind = DateTimeKind.Local) And Not timeZone.Equals(TimeZoneInfo.Local) Then
         ambiguousTime = TimeZoneInfo.ConvertTime(ambiguousTime, TimeZoneInfo.Local, timeZone)
      ' UTC time where timeZone is not UTC zone   
      ElseIf (ambiguousTime.Kind = DateTimeKind.Utc) And Not timeZone.Equals(TimeZoneInfo.Utc) Then
         ambiguousTime = TimeZoneInfo.ConvertTime(ambiguousTime, TimeZoneInfo.Utc, timeZone)
      End If       
      ' Display each offset and its mapping to UTC
      For Each offset As TimeSpan In offsets
         If offset.Equals(timeZone.BaseUtcOffset) Then
            Console.WriteLine("If {0} is {1}, {2} UTC", ambiguousTime, timeZone.StandardName, ambiguousTime - offset)
         Else
            Console.WriteLine("If {0} is {1}, {2} UTC", ambiguousTime, timeZone.DaylightName, ambiguousTime - offset)
         End If   
      Next
   End If            
End Sub

The method can then be called using code such as the following:

Console.WriteLine();
ShowPossibleUtcTimes(new DateTime(2007, 11, 4, 1, 0, 0), 
                     TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time"));
Console.WriteLine();
ShowPossibleUtcTimes(new DateTime(2007, 11, 4, 01, 00, 00, DateTimeKind.Local), 
                     TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time"));
Console.WriteLine();
ShowPossibleUtcTimes(new DateTime(2007, 11, 4, 00, 00, 00, DateTimeKind.Local), 
                     TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time"));
Console.WriteLine();                     
ShowPossibleUtcTimes(new DateTime(2007, 11, 4, 01, 00, 00, DateTimeKind.Unspecified), 
                     TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time"));
Console.WriteLine();
ShowPossibleUtcTimes(new DateTime(2007, 11, 4, 07, 00, 00, DateTimeKind.Utc), 
                     TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time"));
// 
// This example produces the following output if run in the Pacific time zone:
//
//    11/4/2007 1:00:00 AM (GMT-06:00) Central Time (US & Canada) maps to the following possible times:
//    If 11/4/2007 1:00:00 AM is Central Standard Time, 11/4/2007 7:00:00 AM UTC
//    If 11/4/2007 1:00:00 AM is Central Daylight Time, 11/4/2007 6:00:00 AM UTC
//       
//    11/4/2007 1:00:00 AM Pacific Standard Time is not ambiguous in time zone (GMT-06:00) Central Time (US & Canada).
//     
//    11/4/2007 12:00:00 AM local time maps to the following possible times:
//    If 11/4/2007 1:00:00 AM is Central Standard Time, 11/4/2007 7:00:00 AM UTC
//    If 11/4/2007 1:00:00 AM is Central Daylight Time, 11/4/2007 6:00:00 AM UTC
//    
//    11/4/2007 1:00:00 AM (GMT-06:00) Central Time (US & Canada) maps to the following possible times:
//    If 11/4/2007 1:00:00 AM is Central Standard Time, 11/4/2007 7:00:00 AM UTC
//    If 11/4/2007 1:00:00 AM is Central Daylight Time, 11/4/2007 6:00:00 AM UTC
//       
//    11/4/2007 7:00:00 AM UTC maps to the following possible times:
//    If 11/4/2007 1:00:00 AM is Central Standard Time, 11/4/2007 7:00:00 AM UTC
//    If 11/4/2007 1:00:00 AM is Central Daylight Time, 11/4/2007 6:00:00 AM UTC
//

printfn ""
showPossibleUtcTimes(DateTime(2007, 11, 4, 1, 0, 0)) (TimeZoneInfo.FindSystemTimeZoneById "Central Standard Time")
printfn ""
showPossibleUtcTimes (DateTime(2007, 11, 4, 01, 00, 00, DateTimeKind.Local)) (TimeZoneInfo.FindSystemTimeZoneById "Central Standard Time")
printfn ""
showPossibleUtcTimes (DateTime(2007, 11, 4, 00, 00, 00, DateTimeKind.Local)) (TimeZoneInfo.FindSystemTimeZoneById "Central Standard Time")
printfn ""                     
showPossibleUtcTimes (DateTime(2007, 11, 4, 01, 00, 00, DateTimeKind.Unspecified)) (TimeZoneInfo.FindSystemTimeZoneById "Central Standard Time")
printfn ""
showPossibleUtcTimes (DateTime(2007, 11, 4, 07, 00, 00, DateTimeKind.Utc)) (TimeZoneInfo.FindSystemTimeZoneById "Central Standard Time")

// This example produces the following output if run in the Pacific time zone:
//
//    11/4/2007 1:00:00 AM (GMT-06:00) Central Time (US & Canada) maps to the following possible times:
//    If 11/4/2007 1:00:00 AM is Central Standard Time, 11/4/2007 7:00:00 AM UTC
//    If 11/4/2007 1:00:00 AM is Central Daylight Time, 11/4/2007 6:00:00 AM UTC
//       
//    11/4/2007 1:00:00 AM Pacific Standard Time is not ambiguous in time zone (GMT-06:00) Central Time (US & Canada).
//     
//    11/4/2007 12:00:00 AM local time maps to the following possible times:
//    If 11/4/2007 1:00:00 AM is Central Standard Time, 11/4/2007 7:00:00 AM UTC
//    If 11/4/2007 1:00:00 AM is Central Daylight Time, 11/4/2007 6:00:00 AM UTC
//    
//    11/4/2007 1:00:00 AM (GMT-06:00) Central Time (US & Canada) maps to the following possible times:
//    If 11/4/2007 1:00:00 AM is Central Standard Time, 11/4/2007 7:00:00 AM UTC
//    If 11/4/2007 1:00:00 AM is Central Daylight Time, 11/4/2007 6:00:00 AM UTC
//       
//    11/4/2007 7:00:00 AM UTC maps to the following possible times:
//    If 11/4/2007 1:00:00 AM is Central Standard Time, 11/4/2007 7:00:00 AM UTC
//    If 11/4/2007 1:00:00 AM is Central Daylight Time, 11/4/2007 6:00:00 AM UTC
//

ShowPossibleUtcTimes(#11/4/2007 1:00:00#, TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time"))
Console.WriteLine()
ShowPossibleUtcTimes(New Date(2007, 11, 4, 01, 00, 00, DateTimeKind.Local), _
                     TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time"))
Console.WriteLine()
ShowPossibleUtcTimes(New Date(2007, 11, 4, 00, 00, 00, DateTimeKind.Local), _
                     TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time"))
Console.WriteLine()                     
ShowPossibleUtcTimes(New Date(2007, 11, 4, 01, 00, 00, DateTimeKind.Unspecified), _
                     TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time"))
Console.WriteLine()
ShowPossibleUtcTimes(New Date(2007, 11, 4, 07, 00, 00, DateTimeKind.Utc), _
                     TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time"))
' 
' This example produces the following output if run in the Pacific time zone:
'
'    11/4/2007 1:00:00 AM (GMT-06:00) Central Time (US & Canada) maps to the following possible times:
'    If 11/4/2007 1:00:00 AM is Central Standard Time, 11/4/2007 7:00:00 AM UTC
'    If 11/4/2007 1:00:00 AM is Central Daylight Time, 11/4/2007 6:00:00 AM UTC
' 
'    11/4/2007 1:00:00 AM Pacific Standard Time is not ambiguous in time zone (GMT-06:00) Central Time (US & Canada).
' 
'    11/4/2007 12:00:00 AM local time maps to the following possible times:
'    If 11/4/2007 1:00:00 AM is Central Standard Time, 11/4/2007 7:00:00 AM UTC
'    If 11/4/2007 1:00:00 AM is Central Daylight Time, 11/4/2007 6:00:00 AM UTC
' 
'    11/4/2007 1:00:00 AM (GMT-06:00) Central Time (US & Canada) maps to the following possible times:
'    If 11/4/2007 1:00:00 AM is Central Standard Time, 11/4/2007 7:00:00 AM UTC
'    If 11/4/2007 1:00:00 AM is Central Daylight Time, 11/4/2007 6:00:00 AM UTC
' 
'    11/4/2007 7:00:00 AM UTC maps to the following possible times:
'    If 11/4/2007 1:00:00 AM is Central Standard Time, 11/4/2007 7:00:00 AM UTC
'    If 11/4/2007 1:00:00 AM is Central Daylight Time, 11/4/2007 6:00:00 AM UTC

Remarks

The precise behavior of this method depends on the relationship between the Kind property and the TimeZoneInfo object, as the following table shows.

TimeZoneInfo object type	Kind property value	Behavior
TimeZoneInfo.Local	DateTimeKind.Local or DateTimeKind.Unspecified	Returns ambiguous time offsets for `dateTime`.
TimeZoneInfo.Local	DateTimeKind.Utc	Converts `dateTime` to the local time, and then returns ambiguous time offsets for that time.
TimeZoneInfo.Utc	Any value.	Throws an ArgumentException.
Any other time zone.	Local or DateTimeKind.Utc	Converts `dateTime` to the specified time zone, and then determines whether that time is ambiguous.
Any other time zone.	DateTimeKind.Unspecified	Determines whether `dateTime` is ambiguous in the specified time zone.

The order of TimeSpan objects in the array returned by this method is undefined. However, you can determine which element represents an offset from the time zone's standard time by comparing its value with the time zone's BaseUtcOffset property. To map an ambiguous time to a time zone's standard time, see How to: Resolve Ambiguous Times.

Applies to

GetAmbiguousTimeOffsets(DateTimeOffset)

Source:: TimeZoneInfo.cs

Source:: TimeZoneInfo.cs

Source:: TimeZoneInfo.cs

Returns information about the possible dates and times that an ambiguous date and time can be mapped to.

public:
 cli::array <TimeSpan> ^ GetAmbiguousTimeOffsets(DateTimeOffset dateTimeOffset);

public TimeSpan[] GetAmbiguousTimeOffsets (DateTimeOffset dateTimeOffset);

member this.GetAmbiguousTimeOffsets : DateTimeOffset -> TimeSpan[]

Public Function GetAmbiguousTimeOffsets (dateTimeOffset As DateTimeOffset) As TimeSpan()

Parameters

dateTimeOffset: DateTimeOffset

A date and time.

Returns

TimeSpan[]

An array of objects that represents possible Coordinated Universal Time (UTC) offsets that a particular date and time can be mapped to.

Exceptions

ArgumentException

dateTimeOffset is not an ambiguous time.

Remarks

The precise behavior of this method depends on the relationship between the Offset property of the dateTimeOffset parameter and the TimeZoneInfo object. If the value of the Offset property corresponds to the current time zone's possible offsets from Coordinated Universal Time (UTC) for that date and time, the method returns the possible offsets. Otherwise, it converts dateTimeOffset to the time in the current time zone, and then returns the possible offsets of that date and time.

Applies to

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TimeZoneInfo.GetAmbiguousTimeOffsets Method

Definition

Overloads

GetAmbiguousTimeOffsets(DateTime)

Parameters

Returns

Exceptions

Examples

Remarks

See also

Applies to

GetAmbiguousTimeOffsets(DateTimeOffset)

Parameters

Returns

Exceptions

Remarks

See also

Applies to

Additional resources