DateTime.ToUniversalTime DateTime.ToUniversalTime DateTime.ToUniversalTime DateTime.ToUniversalTime Method

Définition

Convertit la valeur de l'objet DateTime actuel en Temps universel coordonné (UTC).Converts the value of the current DateTime object to Coordinated Universal Time (UTC).

public:
 DateTime ToUniversalTime();
public DateTime ToUniversalTime ();
member this.ToUniversalTime : unit -> DateTime
Public Function ToUniversalTime () As DateTime

Retours

Objet dont la propriété Kind est Utc et dont la valeur est l'heure UTC équivalente à la valeur de l'objet DateTime actuel, ou MaxValue si la valeur convertie est trop grande pour être représentée par un objet DateTime, ou MinValue si la valeur convertie est trop petite pour être représentée par un objet DateTime.An object whose Kind property is Utc, and whose value is the UTC equivalent to the value of the current DateTime object, or MaxValue if the converted value is too large to be represented by a DateTime object, or MinValue if the converted value is too small to be represented by a DateTime object.

Exemples

L’exemple suivant illustre la ToUniversalTime méthode.The following example demonstrates the ToUniversalTime method.

using namespace System;

void main()
{
   Console::WriteLine("Enter a date and time.");
   String^ strDateTime = Console::ReadLine();

   DateTime localDateTime, univDateTime;
   try
   {
      localDateTime = DateTime::Parse(strDateTime);
      univDateTime = localDateTime.ToUniversalTime();
    
      Console::WriteLine("{0} local time is {1} universal time.",
                         localDateTime, univDateTime );
   }
   catch (FormatException^) 
   {
      Console::WriteLine("Invalid format.");
      return;
   }

   Console::WriteLine("Enter a date and time in universal time.");
   strDateTime = Console::ReadLine();

   try
   {
      univDateTime = DateTime::Parse(strDateTime);
      localDateTime = univDateTime.ToLocalTime();
  
      Console::WriteLine("{0} universal time is {1} local time.",
                         univDateTime, localDateTime );
   }
   catch (FormatException^) 
   {
      Console::WriteLine("Invalid format.");
      return;
   }
}
// The example displays output like the following when run on a 
// computer whose culture is en-US in the Pacific Standard Time zone:
//     Enter a date and time.
//     12/10/2015 6:18 AM
//     12/10/2015 6:18:00 AM local time is 12/10/2015 2:18:00 PM universal time.
//     Enter a date and time in universal time.
//     12/20/2015 6:42:00
//     12/20/2015 6:42:00 AM universal time is 12/19/2015 10:42:00 PM local time.
using System;

class Example
{
	static void Main()
	{
		DateTime localDateTime, univDateTime;
		
		Console.WriteLine("Enter a date and time.");
		string strDateTime = Console.ReadLine();

		try {
			localDateTime = DateTime.Parse(strDateTime);
    		univDateTime = localDateTime.ToUniversalTime();
    
    		Console.WriteLine("{0} local time is {1} universal time.",
   								localDateTime,
    								univDateTime); 
		}
		catch (FormatException) {
			Console.WriteLine("Invalid format.");
			return;
		}

		Console.WriteLine("Enter a date and time in universal time.");
		strDateTime = Console.ReadLine();

		try {
			univDateTime = DateTime.Parse(strDateTime);
    		localDateTime = univDateTime.ToLocalTime();
    
    		Console.WriteLine("{0} universal time is {1} local time.",
    								 univDateTime,
    								 localDateTime); 
		}
		catch (FormatException) {
			Console.WriteLine("Invalid format.");
			return;
		}

	}
}
// The example displays output like the following when run on a 
// computer whose culture is en-US in the Pacific Standard Time zone:
//     Enter a date and time.
//     12/10/2015 6:18 AM
//     12/10/2015 6:18:00 AM local time is 12/10/2015 2:18:00 PM universal time.
//     Enter a date and time in universal time.
//     12/20/2015 6:42:00
//     12/20/2015 6:42:00 AM universal time is 12/19/2015 10:42:00 PM local time.
Module Example
    Sub Main()
      Dim localDateTime, univDateTime As DateTime
      
      Console.WriteLine("Enter a date and time.")
      Dim strDateTime As String = Console.ReadLine()
      Try
         localDateTime = DateTime.Parse(strDateTime)
         univDateTime = localDateTime.ToUniversalTime()
         Console.WriteLine("{0} local time is {1} universal time.", 
                           localDateTime, univDateTime)
      Catch exp As FormatException
         Console.WriteLine("Invalid format.")
      End Try

      Console.WriteLine("Enter a date and time in universal time.")
      strDateTime = Console.ReadLine()
      Try
         univDateTime = DateTime.Parse(strDateTime)
         localDateTime = univDateTime.ToLocalTime()
  
         Console.WriteLine("{0} universal time is {1} local time.", _
                           univDateTime, localDateTime)
      Catch exp As FormatException
         Console.WriteLine("Invalid format.")
      End Try
    End Sub
End Module
' The example displays output like the following when run on a 
' computer whose culture is en-US in the Pacific Standard Time zone:
'     Enter a date and time.
'     12/10/2015 6:18 AM
'     12/10/2015 6:18:00 AM local time is 12/10/2015 2:18:00 PM universal time.
'     Enter a date and time in universal time.
'     12/20/2015 6:42:00
'     12/20/2015 6:42:00 AM universal time is 12/19/2015 10:42:00 PM local time.

L’exemple suivant utilise la SpecifyKind méthode pour illustrer la Kind façon dont la ToLocalTime propriété ToUniversalTime influence les méthodes de conversion et.The following example uses the SpecifyKind method to demonstrate how the Kind property influences the ToLocalTime and ToUniversalTime conversion methods.

// This code example demonstrates the DateTime Kind, Now, and
// UtcNow properties, and the SpecifyKind(), ToLocalTime(), 
// and ToUniversalTime() methods.

using System;

class Sample 
{
    public static void Main() 
    {
// Get the date and time for the current moment, adjusted 
// to the local time zone.

    DateTime saveNow = DateTime.Now;

// Get the date and time for the current moment expressed 
// as coordinated universal time (UTC).

    DateTime saveUtcNow = DateTime.UtcNow;
    DateTime myDt;

// Display the value and Kind property of the current moment 
// expressed as UTC and local time.

    DisplayNow("UtcNow: ..........", saveUtcNow);
    DisplayNow("Now: .............", saveNow);
    Console.WriteLine();

// Change the Kind property of the current moment to 
// DateTimeKind.Utc and display the result.

    myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Utc);
    Display("Utc: .............", myDt);

// Change the Kind property of the current moment to 
// DateTimeKind.Local and display the result.

    myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Local);
    Display("Local: ...........", myDt);

// Change the Kind property of the current moment to 
// DateTimeKind.Unspecified and display the result.

    myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Unspecified);
    Display("Unspecified: .....", myDt);
    }

// Display the value and Kind property of a DateTime structure, the 
// DateTime structure converted to local time, and the DateTime 
// structure converted to universal time. 

    public static string datePatt = @"M/d/yyyy hh:mm:ss tt";
    public static void Display(string title, DateTime inputDt)
    {
    DateTime dispDt = inputDt;
    string dtString;

// Display the original DateTime.

    dtString = dispDt.ToString(datePatt);
    Console.WriteLine("{0} {1}, Kind = {2}", 
                      title, dtString, dispDt.Kind);

// Convert inputDt to local time and display the result. 
// If inputDt.Kind is DateTimeKind.Utc, the conversion is performed.
// If inputDt.Kind is DateTimeKind.Local, the conversion is not performed.
// If inputDt.Kind is DateTimeKind.Unspecified, the conversion is 
// performed as if inputDt was universal time.

    dispDt = inputDt.ToLocalTime();
    dtString = dispDt.ToString(datePatt);
    Console.WriteLine("  ToLocalTime:     {0}, Kind = {1}", 
                      dtString, dispDt.Kind);

// Convert inputDt to universal time and display the result. 
// If inputDt.Kind is DateTimeKind.Utc, the conversion is not performed.
// If inputDt.Kind is DateTimeKind.Local, the conversion is performed.
// If inputDt.Kind is DateTimeKind.Unspecified, the conversion is 
// performed as if inputDt was local time.

    dispDt = inputDt.ToUniversalTime();
    dtString = dispDt.ToString(datePatt);
    Console.WriteLine("  ToUniversalTime: {0}, Kind = {1}", 
                      dtString, dispDt.Kind);
    Console.WriteLine();
    }

// Display the value and Kind property for DateTime.Now and DateTime.UtcNow.

    public static void DisplayNow(string title, DateTime inputDt)
    {
    string dtString = inputDt.ToString(datePatt);
    Console.WriteLine("{0} {1}, Kind = {2}", 
                      title, dtString, inputDt.Kind);
    }
}

/*
This code example produces the following results:

UtcNow: .......... 5/6/2005 09:34:42 PM, Kind = Utc
Now: ............. 5/6/2005 02:34:42 PM, Kind = Local

Utc: ............. 5/6/2005 02:34:42 PM, Kind = Utc
  ToLocalTime:     5/6/2005 07:34:42 AM, Kind = Local
  ToUniversalTime: 5/6/2005 02:34:42 PM, Kind = Utc

Local: ........... 5/6/2005 02:34:42 PM, Kind = Local
  ToLocalTime:     5/6/2005 02:34:42 PM, Kind = Local
  ToUniversalTime: 5/6/2005 09:34:42 PM, Kind = Utc

Unspecified: ..... 5/6/2005 02:34:42 PM, Kind = Unspecified
  ToLocalTime:     5/6/2005 07:34:42 AM, Kind = Local
  ToUniversalTime: 5/6/2005 09:34:42 PM, Kind = Utc

*/

' This code example demonstrates the DateTime Kind, Now, and
' UtcNow properties, and the SpecifyKind(), ToLocalTime(), 
' and ToUniversalTime() methods.
Class Sample
    Public Shared Sub Main() 
        ' Get the date and time for the current moment, adjusted 
        ' to the local time zone.
        Dim saveNow As DateTime = DateTime.Now
        
        ' Get the date and time for the current moment expressed 
        ' as coordinated universal time (UTC).
        Dim saveUtcNow As DateTime = DateTime.UtcNow
        Dim myDt As DateTime
        
        ' Display the value and Kind property of the current moment 
        ' expressed as UTC and local time.
        DisplayNow("UtcNow: ..........", saveUtcNow)
        DisplayNow("Now: .............", saveNow)
        Console.WriteLine()
        
        ' Change the Kind property of the current moment to 
        ' DateTimeKind.Utc and display the result.
        myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Utc)
        Display("Utc: .............", myDt)
        
        ' Change the Kind property of the current moment to 
        ' DateTimeKind.Local and display the result.
        myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Local)
        Display("Local: ...........", myDt)
        
        ' Change the Kind property of the current moment to 
        ' DateTimeKind.Unspecified and display the result.
        myDt = DateTime.SpecifyKind(saveNow, DateTimeKind.Unspecified)
        Display("Unspecified: .....", myDt)
    End Sub 'Main
    
    ' Display the value and Kind property of a DateTime structure, the 
    ' DateTime structure converted to local time, and the DateTime 
    ' structure converted to universal time. 

    Public Shared datePatt As String = "M/d/yyyy hh:mm:ss tt"
    
    Public Shared Sub Display(ByVal title As String, ByVal inputDt As DateTime) 
        Dim dispDt As DateTime = inputDt
        Dim dtString As String
        
        ' Display the original DateTime.
        dtString = dispDt.ToString(datePatt)
        Console.WriteLine("{0} {1}, Kind = {2}", title, dtString, dispDt.Kind)
        
        ' Convert inputDt to local time and display the result. 
        ' If inputDt.Kind is DateTimeKind.Utc, the conversion is performed.
        ' If inputDt.Kind is DateTimeKind.Local, the conversion is not performed.
        ' If inputDt.Kind is DateTimeKind.Unspecified, the conversion is 
        ' performed as if inputDt was universal time.
        dispDt = inputDt.ToLocalTime()
        dtString = dispDt.ToString(datePatt)
        Console.WriteLine("  ToLocalTime:     {0}, Kind = {1}", dtString, dispDt.Kind)
        
        ' Convert inputDt to universal time and display the result. 
        ' If inputDt.Kind is DateTimeKind.Utc, the conversion is not performed.
        ' If inputDt.Kind is DateTimeKind.Local, the conversion is performed.
        ' If inputDt.Kind is DateTimeKind.Unspecified, the conversion is 
        ' performed as if inputDt was local time.
        dispDt = inputDt.ToUniversalTime()
        dtString = dispDt.ToString(datePatt)
        Console.WriteLine("  ToUniversalTime: {0}, Kind = {1}", dtString, dispDt.Kind)
        Console.WriteLine()
    End Sub 'Display
    
    
    ' Display the value and Kind property for DateTime.Now and DateTime.UtcNow.

    Public Shared Sub DisplayNow(ByVal title As String, ByVal inputDt As DateTime) 
        Dim dtString As String = inputDt.ToString(datePatt)
        Console.WriteLine("{0} {1}, Kind = {2}", title, dtString, inputDt.Kind)
    End Sub 'DisplayNow
End Class 'Sample

'
'This code example produces the following results:
'
'UtcNow: .......... 5/6/2005 09:34:42 PM, Kind = Utc
'Now: ............. 5/6/2005 02:34:42 PM, Kind = Local
'
'Utc: ............. 5/6/2005 02:34:42 PM, Kind = Utc
'  ToLocalTime:     5/6/2005 07:34:42 AM, Kind = Local
'  ToUniversalTime: 5/6/2005 02:34:42 PM, Kind = Utc
'
'Local: ........... 5/6/2005 02:34:42 PM, Kind = Local
'  ToLocalTime:     5/6/2005 02:34:42 PM, Kind = Local
'  ToUniversalTime: 5/6/2005 09:34:42 PM, Kind = Utc
'
'Unspecified: ..... 5/6/2005 02:34:42 PM, Kind = Unspecified
'  ToLocalTime:     5/6/2005 07:34:42 AM, Kind = Local
'  ToUniversalTime: 5/6/2005 09:34:42 PM, Kind = Utc
'

Remarques

L’heure universelle coordonnée (UTC) est égale à l’heure locale moins l’offset UTC.The Coordinated Universal Time (UTC) is equal to the local time minus the UTC offset. Pour plus d’informations sur le décalage UTC, TimeZone.GetUtcOffsetconsultez.For more information about the UTC offset, see TimeZone.GetUtcOffset. La conversion prend également en compte la règle d’heure d’été qui s’applique à l’heure représentée par DateTime l’objet actuel.The conversion also takes into account the daylight saving time rule that applies to the time represented by the current DateTime object.

Important

Sur Windows XPWindows XP les systèmes, ToUniversalTime la méthode reconnaît uniquement la règle d’ajustement en cours lors de la conversion de l’heure locale en heure UTC.On Windows XPWindows XP systems, the ToUniversalTime method recognizes only the current adjustment rule when converting from local time to UTC. Par conséquent, les conversions pour les périodes avant l’apparition de la règle d’ajustement actuelle peuvent ne pas refléter avec précision la différence entre l’heure locale et le temps universel coordonné (UTC).As a result, conversions for periods before the current adjustment rule came into effect may not accurately reflect the difference between local time and UTC.

À partir de la version .NET Framework 2,0, la valeur retournée ToUniversalTime par la méthode est déterminée Kind par la propriété de DateTime l’objet actuel.Starting with the .NET Framework version 2.0, the value returned by the ToUniversalTime method is determined by the Kind property of the current DateTime object. Le tableau suivant décrit les résultats possibles.The following table describes the possible results.

KindKind RésultatsResults
Utc Aucune conversion n’est effectuée.No conversion is performed.
Local L’objet DateTime actuel est converti en temps universel coordonné (UTC).The current DateTime object is converted to UTC.
Unspecified L’objet DateTime actuel est supposé être une heure locale, et la conversion est effectuée comme si Kind était Local.The current DateTime object is assumed to be a local time, and the conversion is performed as if Kind were Local.

Notes

La ToUniversalTime méthode convertit DateTime une valeur de heure locale en heure UTC.The ToUniversalTime method converts a DateTime value from local time to UTC. Pour convertir l’heure d’un fuseau horaire non local en heure UTC, utilisez la TimeZoneInfo.ConvertTimeToUtc(DateTime, TimeZoneInfo) méthode.To convert the time in a non-local time zone to UTC, use the TimeZoneInfo.ConvertTimeToUtc(DateTime, TimeZoneInfo) method. Pour convertir une heure dont le décalage par rapport à l’heure UTC ToUniversalTime est connu, utilisez la méthode.To convert a time whose offset from UTC is known, use the ToUniversalTime method.

Si la valeur d’instance de date et d’heure est une heure ambiguë, cette méthode suppose qu’il s’agit d’une heure standard.If the date and time instance value is an ambiguous time, this method assumes that it is a standard time. (Une heure ambiguë est une heure qui peut être mappée à une heure d’hiver ou à une heure d’été dans le fuseau horaire local) Si la valeur de l’instance de date et d’heure n’est pas valide, cette méthode soustrait simplement l’heure locale du décalage UTC du fuseau horaire local pour retourner le temps universel (UTC).(An ambiguous time is one that can map either to a standard time or to a daylight saving time in the local time zone) If the date and time instance value is an invalid time, this method simply subtracts the local time from the local time zone's UTC offset to return UTC. (Une heure non valide est une heure qui n’existe pas en raison de l’application des règles d’ajustement de l’heure d’été.)(An invalid time is one that does not exist because of the application of daylight saving time adjustment rules.)

Notes pour les appelants

La ToUniversalTime() méthode est parfois utilisée pour convertir une heure locale en heure UTC.The ToUniversalTime() method is sometimes used to convert a local time to UTC. La ToLocalTime() méthode est ensuite appelée pour restaurer l’heure locale d’origine.The ToLocalTime() method is then called to restore the original local time. Toutefois, si l’heure d’origine représente une heure non valide dans le fuseau horaire local, les deux valeurs d’heure locales ne sont pas égales.However, if the original time represents an invalid time in the local time zone, the two local time values will not be equal. Pour obtenir des informations supplémentaires et un exemple, ToLocalTime() consultez la méthode.For additional information and an example, see the ToLocalTime() method.

Sur Windows XPWindows XP les systèmes, ToUniversalTime() la méthode reconnaît uniquement la règle d’ajustement actuelle pour le fuseau horaire local, qui s’applique à toutes les dates, y compris les dates de niveau inférieur (autrement dit, les dates antérieures à la date de début de l’ajustement actuel). règle).On Windows XPWindows XP systems, the ToUniversalTime() method recognizes only the current adjustment rule for the local time zone, which it applies to all dates, including down-level dates (that is, dates that are earlier than the starting date of the current adjustment rule). Les applications qui Windows XPWindows XP s’exécutent sur qui requièrent des calculs de date et d’heure locaux exactes FindSystemTimeZoneById(String) doivent contourner ce TimeZoneInfo comportement en utilisant la méthode pour récupérer un objet qui correspond au fuseau horaire local et en appelant sa ConvertTimeToUtc(DateTime, TimeZoneInfo) méthode.Applications running on Windows XPWindows XP that require historically accurate local date and time calculations must work around this behavior by using the FindSystemTimeZoneById(String) method to retrieve a TimeZoneInfo object that corresponds to the local time zone and calling its ConvertTimeToUtc(DateTime, TimeZoneInfo) method.

L’exemple suivant illustre la différence entre les ToUniversalTime() méthodes et ConvertTimeToUtc(DateTime, TimeZoneInfo) sur un Windows XPWindows XP système situé dans le fuseau horaire Pacifique (États-Unis).The following example illustrates the difference between the ToUniversalTime() and ConvertTimeToUtc(DateTime, TimeZoneInfo) methods on a Windows XPWindows XP system in the U.S. Pacific Time zone. Les deux premiers appels de méthode appliquent la règle d’ajustement de fuseau horaire en cours (qui a pris effet dans 2007) à une date dans 2006.The first two method calls apply the current time zone adjustment rule (which went into effect in 2007) to a date in 2006. La règle d’ajustement actuelle fournit le passage à l’heure d’été le deuxième dimanche de mars ; la règle précédente, qui était en vigueur dans 2006, a été fournie pour le passage à l’heure d’été au premier dimanche d’avril.The current adjustment rule provides for the transition to daylight saving time on the second Sunday of March; the previous rule, which was in effect in 2006, provided for the transition to daylight saving time to occur on the first Sunday of April. Seul le troisième appel de méthode effectue avec précision cette conversion historique de la date et de l’heure.Only the third method call accurately performs this historical date and time conversion.

[!code-csharpSystem.DateTime.ToUniversalTime#1] [!code-vbSystem.DateTime.ToUniversalTime#1][!code-csharpSystem.DateTime.ToUniversalTime#1] [!code-vbSystem.DateTime.ToUniversalTime#1]

S’applique à

Voir aussi