作法:建立有調整規則的時區

應用程式所需的精確時區資訊,可能因為以下數個原因,而不存在於特定系統上:

  • 從未在本機系統的登錄中定義過時區。

  • 已從登錄修改或移除時區的相關資料。

  • 時區沒有特定歷史時期時區調整的準確資訊。

在這些情況下,可以呼叫 CreateCustomTimeZone 方法,定義應用程式所需的時區。 您可以使用此方法的多載來建立有或沒有調整規則的時區。 若時區支援日光節約時間,則您可使用固定或浮動調整規則來定義調整。 (如需了解這些字詞的定義,請參閱時區概觀中的 "Time Zone Terminology" 一節。)

重要

呼叫 CreateCustomTimeZone 方法所建立的自訂時區,不會新增至登錄。 相反地,只能透過呼叫 CreateCustomTimeZone 方法所傳回的物件參考,加以存取。

本主題說明如何建立具有調整規則時區。 若要建立不支援日光節約時間調整規則的時區,請參閱操作說明:建立沒有調整規則的時區

若要建立有浮動調整規則的時區

  1. 為每項調整 (也就是每隔特定時間間隔,轉換回標準時間或從標準時間轉換),執行下列動作:

    1. 定義時區調整的開始轉換時間。

      您必須呼叫 TimeZoneInfo.TransitionTime.CreateFloatingDateRule 方法,並對其傳遞一個 DateTime 值,定義轉換時間、定義轉換月份的整數值、定義轉換發生之週數的整數值,以及 DayOfWeek 值,定義發生轉換當週的星期幾。 這個方法呼叫會具現化 TimeZoneInfo.TransitionTime 物件。

    2. 定義時區調整的結束轉換時間。 這需要再呼叫一次 TimeZoneInfo.TransitionTime.CreateFloatingDateRule 方法。 這個方法呼叫會具現化第二個 TimeZoneInfo.TransitionTime 物件。

    3. 呼叫 CreateAdjustmentRule 方法,並對其傳遞調整的有效開始和結束日期、定義轉換多少時間的 TimeZoneInfo.TransitionTime 物件,以及兩個 TimeSpan 物件,定義何時轉換到日光節約時間或從日光節約時間轉換。 這個方法呼叫會具現化 TimeZoneInfo.AdjustmentRule 物件。

    4. TimeZoneInfo.AdjustmentRule 物件指派給 TimeZoneInfo.AdjustmentRule 物件的陣列。

  2. 定義時區的顯示名稱。 顯示名稱會遵循相當標準的格式,其中時區與國際標準時間 (UTC) 的位移會以括弧括住且後面接著一個字串,來識別時區、時區中的一或多個城市,或時區中的一或多個國家或地區。

  3. 定義時區標準時間的名稱。 一般而言,此字串也用作為該時區的識別碼。

  4. 定義該時區日光節約時間的名稱。

  5. 如果想要使用與時區標準名稱不同的識別碼,請定義時區識別碼。

  6. 具現化定義時區與 UTC 之位移的 TimeSpan 物件。 時間比 UTC 晚的時區,時區位移為正數。 時間比 UTC 早的時區,時區位移為負數。

  7. 呼叫 TimeZoneInfo.CreateCustomTimeZone(String, TimeSpan, String, String, String, TimeZoneInfo+AdjustmentRule[]) 方法,具現化新的時區。

範例

下列範例定義美國中部標準時區,包含從 1918 年到目前的各種時間間隔調整規則。

TimeZoneInfo cst;
// Declare necessary TimeZoneInfo.AdjustmentRule objects for time zone
TimeSpan delta = new TimeSpan(1, 0, 0);
TimeZoneInfo.AdjustmentRule adjustment;
List<TimeZoneInfo.AdjustmentRule> adjustmentList = new List<TimeZoneInfo.AdjustmentRule>();
// Declare transition time variables to hold transition time information
TimeZoneInfo.TransitionTime transitionRuleStart, transitionRuleEnd;

// Define new Central Standard Time zone 6 hours earlier than UTC
// Define rule 1 (for 1918-1919)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(new DateTime(1, 1, 1, 2, 0, 0), 03, 05, DayOfWeek.Sunday);
transitionRuleEnd = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(new DateTime(1, 1, 1, 2, 0, 0), 10, 05, DayOfWeek.Sunday);
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(new DateTime(1918, 1, 1), new DateTime(1919, 12, 31), delta,
                                                           transitionRuleStart, transitionRuleEnd);
adjustmentList.Add(adjustment);
// Define rule 2 (for 1942)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFixedDateRule(new DateTime(1, 1, 1, 2, 0, 0), 02, 09);
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(new DateTime(1942, 1, 1), new DateTime(1942, 12, 31),
                                                           delta, transitionRuleStart, transitionRuleEnd);
adjustmentList.Add(adjustment);
// Define rule 3 (for 1945)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFixedDateRule(new DateTime(1, 1, 1, 23, 0, 0), 08, 14);
transitionRuleEnd = TimeZoneInfo.TransitionTime.CreateFixedDateRule(new DateTime(1, 1, 1, 2, 0, 0), 09, 30);
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(new DateTime(1945, 1, 1), new DateTime(1945, 12, 31),
                                                           delta, transitionRuleStart, transitionRuleEnd);
adjustmentList.Add(adjustment);
// Define end rule (for 1967-2006)
transitionRuleEnd = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(new DateTime(1, 1, 1, 2, 0, 0), 10, 5, DayOfWeek.Sunday);
// Define rule 4 (for 1967-73)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(new DateTime(1, 1, 1, 2, 0, 0), 04, 05, DayOfWeek.Sunday);
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(new DateTime(1967, 1, 1), new DateTime(1973, 12, 31),
                                                           delta, transitionRuleStart, transitionRuleEnd);
adjustmentList.Add(adjustment);
// Define rule 5 (for 1974 only)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFixedDateRule(new DateTime(1, 1, 1, 2, 0, 0), 01, 06);
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(new DateTime(1974, 1, 1), new DateTime(1974, 12, 31),
                                                           delta, transitionRuleStart, transitionRuleEnd);
adjustmentList.Add(adjustment);
// Define rule 6 (for 1975 only)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFixedDateRule(new DateTime(1, 1, 1, 2, 0, 0), 02, 23);
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(new DateTime(1975, 1, 1), new DateTime(1975, 12, 31),
                                                           delta, transitionRuleStart, transitionRuleEnd);
adjustmentList.Add(adjustment);
// Define rule 7 (1976-1986)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(new DateTime(1, 1, 1, 2, 0, 0), 04, 05, DayOfWeek.Sunday);
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(new DateTime(1976, 1, 1), new DateTime(1986, 12, 31),
                                                           delta, transitionRuleStart, transitionRuleEnd);
adjustmentList.Add(adjustment);
// Define rule 8 (1987-2006)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(new DateTime(1, 1, 1, 2, 0, 0), 04, 01, DayOfWeek.Sunday);
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(new DateTime(1987, 1, 1), new DateTime(2006, 12, 31),
                                                           delta, transitionRuleStart, transitionRuleEnd);
adjustmentList.Add(adjustment);
// Define rule 9 (2007- )
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(new DateTime(1, 1, 1, 2, 0, 0), 03, 02, DayOfWeek.Sunday);
transitionRuleEnd = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(new DateTime(1, 1, 1, 2, 0, 0), 11, 01, DayOfWeek.Sunday);
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(new DateTime(2007, 1, 1), DateTime.MaxValue.Date,
                                                           delta, transitionRuleStart, transitionRuleEnd);
adjustmentList.Add(adjustment);

// Convert list of adjustment rules to an array
TimeZoneInfo.AdjustmentRule[] adjustments = new TimeZoneInfo.AdjustmentRule[adjustmentList.Count];
adjustmentList.CopyTo(adjustments);

cst = TimeZoneInfo.CreateCustomTimeZone("Central Standard Time", new TimeSpan(-6, 0, 0),
      "(GMT-06:00) Central Time (US Only)", "Central Standard Time",
      "Central Daylight Time", adjustments);
Dim cst As TimeZoneInfo
' Declare necessary TimeZoneInfo.AdjustmentRule objects for time zone
Dim delta As New TimeSpan(1, 0, 0)
Dim adjustment As TimeZoneInfo.AdjustmentRule
Dim adjustmentList As New List(Of TimeZoneInfo.AdjustmentRule)
' Declare transition time variables to hold transition time information
Dim transitionRuleStart, transitionRuleEnd As TimeZoneInfo.TransitionTime

' Define new Central Standard Time zone 6 hours earlier than UTC
' Define rule 1 (for 1918-1919)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(#02:00:00AM#, 03, 05, DayOfWeek.Sunday)
transitionRuleEnd = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(#02:00:00AM#, 10, 05, DayOfWeek.Sunday)
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(#01/01/1918#, #12/31/1919#, delta, transitionRuleStart, transitionRuleEnd)
adjustmentList.Add(adjustment)
' Define rule 2 (for 1942)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFixedDateRule(#2:00:00AM#, 02, 09)
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(#01/01/1942#, #12/31/1942#, delta, transitionRuleStart, transitionRuleEnd)
adjustmentList.Add(adjustment)
' Define rule 3 (for 1945)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFixedDateRule(#11:00:00PM#, 08, 14)
transitionRuleEnd = TimeZoneInfo.TransitionTime.CreateFixedDateRule(#2:00:00AM#, 09, 30)
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(#01/01/1945#, #12/31/1945#, delta, transitionRuleStart, transitionRuleEnd)
adjustmentList.Add(adjustment)
' Define end rule (for 1967-2006)
transitionRuleEnd = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(#02:00:00AM#, 10, 5, DayOfWeek.Sunday)
' Define rule 4 (for 1967-73)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(#2:00:00AM#, 04, 05, DayOfWeek.Sunday)
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(#01/01/1967#, #12/31/1973#, delta, transitionRuleStart, transitionRuleEnd)
adjustmentList.Add(adjustment)
' Define rule 5 (for 1974 only)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFixedDateRule(#2:00:00AM#, 01, 06)
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(#01/01/1974#, #12/31/1974#, delta, transitionRuleStart, transitionRuleEnd)
adjustmentList.Add(adjustment)
' Define rule 6 (for 1975 only)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFixedDateRule(#2:00:00AM#, 02, 23)
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(#01/01/1975#, #12/31/1975#, delta, transitionRuleStart, transitionRuleEnd)
adjustmentList.Add(adjustment)
' Define rule 7 (1976-1986)
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(#2:00:00AM#, 04, 05, DayOfWeek.Sunday)
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(#01/01/1976#, #12/31/1986#, delta, transitionRuleStart, transitionRuleEnd)
adjustmentList.Add(adjustment)
' Define rule 8 (1987-2006)  
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(#2:00:00AM#, 04, 01, DayOfWeek.Sunday)
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(#01/01/1987#, #12/31/2006#, delta, transitionRuleStart, transitionRuleEnd)
adjustmentList.Add(adjustment)
' Define rule 9 (2007- )  
transitionRuleStart = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(#2:00:00AM#, 03, 02, DayOfWeek.Sunday)
transitionRuleEnd = TimeZoneInfo.TransitionTime.CreateFloatingDateRule(#2:00:00AM#, 11, 01, DayOfWeek.Sunday)
adjustment = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(#01/01/2007#, Date.MaxValue.Date, delta, transitionRuleStart, transitionRuleEnd)
adjustmentList.Add(adjustment)

' Convert list of adjustment rules to an array
Dim adjustments(adjustmentList.Count - 1) As TimeZoneInfo.AdjustmentRule
adjustmentList.CopyTo(adjustments)

cst = TimeZoneInfo.CreateCustomTimeZone("Central Standard Time", New TimeSpan(-6, 0, 0), _
      "(GMT-06:00) Central Time (US Only)", "Central Standard Time", _
      "Central Daylight Time", adjustments)

在此範例中所建立的時區,有多個調整規則。 請務必小心,確保任一調整規則的有效開始和結束日期,不會與另一個調整規則的日期重疊。 如有重疊,會擲回 InvalidTimeZoneException

對浮動調整規則來說,會對方法 CreateFloatingDateRuleweek 參數,傳遞值 5,指出轉換發生在特定月份的最後一週。

在建立用於 TimeZoneInfo.CreateCustomTimeZone(String, TimeSpan, String, String, String, TimeZoneInfo+AdjustmentRule[]) 方法呼叫中的 TimeZoneInfo.AdjustmentRule 物件陣列時,程式碼可以初始化該陣列,使其大小變成替時區所建立之調整數字所需的大小。 相反地,這個程式碼範例會呼叫 Add 方法,對 TimeZoneInfo.AdjustmentRule 物件的泛型 List<T> 集合,新增每個調整規則。 然後,程式碼會呼叫 CopyTo 方法,將這個集合的成員,複製到該陣列。

此範例也使用 CreateFixedDateRule 方法,定義固定日期的調整。 這類似於呼叫 CreateFloatingDateRule 方法,不同之處在於它只需要轉換參數的時間、月份和日期。

使用下列程式碼,可以測試此範例:

TimeZoneInfo est = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");

DateTime pastDate1 = new DateTime(1942, 2, 11);
Console.WriteLine("Is {0} daylight saving time: {1}", pastDate1,
                  cst.IsDaylightSavingTime(pastDate1));

DateTime pastDate2 = new DateTime(1967, 10, 29, 1, 30, 00);
Console.WriteLine("Is {0} ambiguous: {1}", pastDate2,
                  cst.IsAmbiguousTime(pastDate2));

DateTime pastDate3 = new DateTime(1974, 1, 7, 2, 59, 00);
Console.WriteLine("{0} {1} is {2} {3}", pastDate3,
                  est.IsDaylightSavingTime(pastDate3) ?
                      est.DaylightName : est.StandardName,
                  TimeZoneInfo.ConvertTime(pastDate3, est, cst),
                  cst.IsDaylightSavingTime(TimeZoneInfo.ConvertTime(pastDate3, est, cst)) ?
                      cst.DaylightName : cst.StandardName);
//
// This code produces the following output to the console:
//
//    Is 2/11/1942 12:00:00 AM daylight saving time: True
//    Is 10/29/1967 1:30:00 AM ambiguous: True
//    1/7/1974 2:59:00 AM Eastern Standard Time is 1/7/1974 2:59:00 AM Central Daylight Time
Dim est As TimeZoneInfo = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time")

Dim pastDate1 As Date = #2/11/1942#
Console.WriteLine("Is {0} daylight saving time: {1}", pastDate1, _
                  cst.IsDaylightSavingTime(pastDate1))

Dim pastDate2 As Date = #10/29/1967 1:30AM#
Console.WriteLine("Is {0} ambiguous: {1}", pastDate2, _
                  cst.IsAmbiguousTime(pastDate2))

Dim pastDate3 As Date = #1/7/1974 2:59AM#
Console.WriteLine("{0} {1} is {2} {3}", pastDate3, _
                  IIf(est.IsDaylightSavingTime(pastDate3), _
                      est.DaylightName, est.StandardName), _
                  TimeZoneInfo.ConvertTime(pastDate3, est, cst), _
                  IIf(cst.IsDaylightSavingTime(TimeZoneInfo.ConvertTime(pastDate3, est, cst)), _
                      cst.DaylightName, cst.StandardName))
'
' This code produces the following output to the console:
' 
'    Is 2/11/1942 12:00:00 AM daylight saving time: True
'    Is 10/29/1967 1:30:00 AM ambiguous: True
'    1/7/1974 2:59:00 AM Eastern Standard Time is 1/7/1974 2:59:00 AM Central Daylight Time                            

編譯程式碼

這個範例需要:

  • 匯入下列命名空間:

    using System.Collections.Generic;
    using System.Collections.ObjectModel;
    
    Imports System.Collections.Generic
    Imports System.Collections.ObjectModel
    
    

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