TimeZoneInfo.TransitionTime.DayOfWeek Property

Definition

Namespace:

System

Assembly:

System.Runtime.dll

Source:

TimeZoneInfo.TransitionTime.cs

Gets the day of the week on which the time change occurs.

public:
 property DayOfWeek DayOfWeek { DayOfWeek get(); };

public DayOfWeek DayOfWeek { get; }

member this.DayOfWeek : DayOfWeek

Public ReadOnly Property DayOfWeek As DayOfWeek

Property Value

DayOfWeek

The day of the week on which the time change occurs.

Examples

The following example enumerates the time zones found on the local computer and displays transition time information for all floating-date transitions. The time information includes the day of the week on which the time change occurs.

private enum WeekOfMonth
{
   First = 1,
   Second = 2,
   Third = 3,
   Fourth = 4,
   Last = 5
}

private void GetFloatingTransitionTimes()
{
   ReadOnlyCollection<TimeZoneInfo> timeZones = TimeZoneInfo.GetSystemTimeZones();
   foreach (TimeZoneInfo zone in timeZones)
   {
      TimeZoneInfo.AdjustmentRule[] adjustmentRules = zone.GetAdjustmentRules();
      DateTimeFormatInfo dateInfo = CultureInfo.CurrentCulture.DateTimeFormat;
      foreach (TimeZoneInfo.AdjustmentRule adjustmentRule in adjustmentRules)
      {
         TimeZoneInfo.TransitionTime daylightStart = adjustmentRule.DaylightTransitionStart;
         if (! daylightStart.IsFixedDateRule)
            Console.WriteLine("{0}, {1:d}-{2:d}: Begins at {3:t} on the {4} {5} of {6}.", 
                              zone.StandardName, 
                              adjustmentRule.DateStart, 
                              adjustmentRule.DateEnd,                                 
                              daylightStart.TimeOfDay, 
                              ((WeekOfMonth)daylightStart.Week).ToString(),  
                              daylightStart.DayOfWeek.ToString(),
                              dateInfo.GetMonthName(daylightStart.Month));

         TimeZoneInfo.TransitionTime daylightEnd = adjustmentRule.DaylightTransitionEnd;
         if (! daylightEnd.IsFixedDateRule)
            Console.WriteLine("{0}, {1:d}-{2:d}: Ends at {3:t} on the {4} {5} of {6}.", 
                              zone.StandardName, 
                              adjustmentRule.DateStart, 
                              adjustmentRule.DateEnd,                                 
                              daylightEnd.TimeOfDay, 
                              ((WeekOfMonth)daylightEnd.Week).ToString(),  
                              daylightEnd.DayOfWeek.ToString(), 
                              dateInfo.GetMonthName(daylightEnd.Month));
      }
   }   
}

type WeekOfMonth =
    | First = 1
    | Second = 2
    | Third = 3
    | Fourth = 4
    | Last = 5

let getFloatingTransitionTimes () =
    let timeZones = TimeZoneInfo.GetSystemTimeZones()
    for zone in timeZones do
        let adjustmentRules = zone.GetAdjustmentRules()
        let dateInfo = CultureInfo.CurrentCulture.DateTimeFormat
        for adjustmentRule in adjustmentRules do
            let daylightStart = adjustmentRule.DaylightTransitionStart
            if not daylightStart.IsFixedDateRule then
                printfn $"{zone.StandardName}, {adjustmentRule.DateStart:d}-{adjustmentRule.DateEnd:d}: Begins at {daylightStart.TimeOfDay:t} on the {enum<WeekOfMonth> daylightStart.Week} {daylightStart.DayOfWeek} of {dateInfo.GetMonthName daylightStart.Month}." 
            
            let daylightEnd = adjustmentRule.DaylightTransitionEnd
            if not daylightEnd.IsFixedDateRule then
                printfn $"{zone.StandardName}, {adjustmentRule.DateStart:d}-{adjustmentRule.DateEnd:d}: Ends at {daylightEnd.TimeOfDay:t} on the {enum<WeekOfMonth> daylightEnd.Week} {daylightEnd.DayOfWeek} of {dateInfo.GetMonthName daylightEnd.Month}."

Private Enum WeekOfMonth As Integer
   First = 1
   Second = 2
   Third = 3
   Fourth = 4
   Last = 5 
End Enum

Private Sub GetFloatingTransitionTimes()
   Dim timeZones As ReadOnlyCollection(Of TimeZoneInfo) = TimeZoneInfo.GetSystemTimeZones()
   For Each zone As TimeZoneInfo In timeZones
      Dim adjustmentRules() As TimeZoneInfo.AdjustmentRule = zone.GetAdjustmentRules()
      For Each adjustmentRule As TimeZoneInfo.AdjustmentRule in adjustmentRules
         Dim daylightStart As TimeZoneInfo.TransitionTime = adjustmentRule.DaylightTransitionStart
         If Not daylightStart.IsFixedDateRule Then
            Console.WriteLine("{0}, {1:d}-{2:d}: Begins at {3:t} on the {4} {5} of {6}.", _
                              zone.StandardName, _
                              adjustmentRule.DateStart, _
                              adjustmentRule.DateEnd, _                                 
                              daylightStart.TimeOfDay, _
                              CType(daylightStart.Week, WeekOfMonth).ToString(), _ 
                              daylightStart.DayOfWeek.ToString(), _
                              MonthName(daylightStart.Month))
         End If
         Dim daylightEnd As TimeZoneInfo.TransitionTime = adjustmentRule.DaylightTransitionEnd
         If Not daylightEnd.IsFixedDateRule Then
            Console.WriteLine("{0}, {1:d}-{2:d}: Ends at {3:t} on the {4} {5} of {6}.", _
                              zone.StandardName, _
                              adjustmentRule.DateStart, _
                              adjustmentRule.DateEnd, _                                 
                              daylightEnd.TimeOfDay, _
                              CType(daylightEnd.Week, WeekOfMonth).ToString(), _ 
                              daylightEnd.DayOfWeek.ToString(), _
                              MonthName(daylightEnd.Month))
         End If   
      Next
   Next   
End Sub

Remarks

The DayOfWeek property returns a valid value only if the IsFixedDateRule property is false.

The DayOfWeek property indicates the day of the week on which a floating-date rule is applied (for example, the second Sunday of November). In contrast, the Day property indicates the day of the month on which a fixed-date rule is applied (for example, April 15).