throw new NotImplementedException ();
}
+ public bool IsInvalidTime (DateTime dateTime)
+ {
+ if (dateTime.Kind == DateTimeKind.Utc)
+ return false;
+ if (dateTime.Kind == DateTimeKind.Local && this != Local)
+ return false;
+
+ AdjustmentRule rule = GetApplicableRule (dateTime);
+ if (rule != null) {
+ DateTime tpoint = TransitionPoint (rule.DaylightTransitionStart, dateTime.Year);
+ if (dateTime >= tpoint && dateTime < tpoint + rule.DaylightDelta)
+ return true;
+ }
+
+ return false;
+ }
+
void IDeserializationCallback.OnDeserialization (object sender)
{
try {
}
#region reference sources
- // Shortcut for TimeZoneInfo.Local.GetUtcOffset
- internal static TimeSpan GetLocalUtcOffset(DateTime dateTime, TimeZoneInfoOptions flags)
- {
- bool dst;
- return Local.GetUtcOffset (dateTime, out dst);
- }
-
- internal TimeSpan GetUtcOffset(DateTime dateTime, TimeZoneInfoOptions flags)
- {
- bool dst;
- return GetUtcOffset (dateTime, out dst);
- }
-
- // used by GetUtcOffsetFromUtc (DateTime.Now, DateTime.ToLocalTime) for max/min whole-day range checks
- private static DateTime s_maxDateOnly = new DateTime(9999, 12, 31);
- private static DateTime s_minDateOnly = new DateTime(1, 1, 2);
-
- static internal TimeSpan GetUtcOffsetFromUtc (DateTime time, TimeZoneInfo zone, out Boolean isDaylightSavings, out Boolean isAmbiguousLocalDst)
- {
- isDaylightSavings = false;
- isAmbiguousLocalDst = false;
- TimeSpan baseOffset = zone.BaseUtcOffset;
- Int32 year;
- AdjustmentRule rule;
-
- if (time > s_maxDateOnly) {
- rule = zone.GetAdjustmentRuleForTime(DateTime.MaxValue);
- year = 9999;
- }
- else if (time < s_minDateOnly) {
- rule = zone.GetAdjustmentRuleForTime(DateTime.MinValue);
- year = 1;
- }
- else {
- DateTime targetTime = time + baseOffset;
- year = time.Year;
- rule = zone.GetAdjustmentRuleForTime(targetTime);
- }
-
- if (rule != null) {
- isDaylightSavings = GetIsDaylightSavingsFromUtc(time, year, zone.baseUtcOffset, rule, out isAmbiguousLocalDst);
- baseOffset += (isDaylightSavings ? rule.DaylightDelta : TimeSpan.Zero /* */);
- }
-
- return baseOffset;
- }
-
- // assumes dateTime is in the current time zone's time
- private AdjustmentRule GetAdjustmentRuleForTime(DateTime dateTime) {
- if (adjustmentRules == null || adjustmentRules.Length == 0) {
- return null;
- }
-
-#if WINXP_AND_WIN2K3_SUPPORT
- // On pre-Vista versions of Windows if you run "cmd /c date" or "cmd /c time" to update the system time
- // the operating system doesn't pick up the correct time zone adjustment rule (it stays on the currently loaded rule).
- // We need to use the OS API data in this scenario instead of the loaded adjustment rules from the registry for
- // consistency. Otherwise DateTime.Now might not match the time displayed in the system tray.
- if (!Environment.IsWindowsVistaOrAbove && s_cachedData.GetCorrespondingKind(this) == DateTimeKind.Local) {
- return s_cachedData.GetOneYearLocalFromLocal(dateTime.Year).rule;
- }
-#endif
- // Only check the whole-date portion of the dateTime -
- // This is because the AdjustmentRule DateStart & DateEnd are stored as
- // Date-only values {4/2/2006 - 10/28/2006} but actually represent the
- // time span {4/2/2006@00:00:00.00000 - 10/28/2006@23:59:59.99999}
- DateTime date = dateTime.Date;
-
- for (int i = 0; i < adjustmentRules.Length; i++) {
- if (adjustmentRules[i].DateStart <= date && adjustmentRules[i].DateEnd >= date) {
- return adjustmentRules[i];
- }
- }
-
- return null;
- }
-
- //
- // GetIsDaylightSavingsFromUtc -
- //
- // Helper function that checks if a given dateTime is in Daylight Saving Time (DST)
- // This function assumes the dateTime is in UTC and AdjustmentRule is in a different time zone
- //
- static private Boolean GetIsDaylightSavingsFromUtc(DateTime time, Int32 Year, TimeSpan utc, AdjustmentRule rule, out Boolean isAmbiguousLocalDst) {
- isAmbiguousLocalDst = false;
-
- if (rule == null) {
- return false;
- }
-
- // Get the daylight changes for the year of the specified time.
- TimeSpan offset = utc; /* */
- DaylightTime daylightTime = GetDaylightTime(Year, rule);
-
- // The start and end times represent the range of universal times that are in DST for that year.
- // Within that there is an ambiguous hour, usually right at the end, but at the beginning in
- // the unusual case of a negative daylight savings delta.
- DateTime startTime = daylightTime.Start - offset;
- DateTime endTime = daylightTime.End - offset - rule.DaylightDelta; /* */
- DateTime ambiguousStart;
- DateTime ambiguousEnd;
- if (daylightTime.Delta.Ticks > 0) {
- ambiguousStart = endTime - daylightTime.Delta;
- ambiguousEnd = endTime;
- } else {
- ambiguousStart = startTime;
- ambiguousEnd = startTime - daylightTime.Delta;
- }
-
- Boolean isDst = CheckIsDst(startTime, time, endTime);
-
- // See if the resulting local time becomes ambiguous. This must be captured here or the
- // DateTime will not be able to round-trip back to UTC accurately.
- if (isDst) {
- isAmbiguousLocalDst = (time >= ambiguousStart && time < ambiguousEnd);
-
- if (!isAmbiguousLocalDst && ambiguousStart.Year != ambiguousEnd.Year) {
- // there exists an extreme corner case where the start or end period is on a year boundary and
- // because of this the comparison above might have been performed for a year-early or a year-later
- // than it should have been.
- DateTime ambiguousStartModified;
- DateTime ambiguousEndModified;
- try {
- ambiguousStartModified = ambiguousStart.AddYears(1);
- ambiguousEndModified = ambiguousEnd.AddYears(1);
- isAmbiguousLocalDst = (time >= ambiguousStart && time < ambiguousEnd);
- }
- catch (ArgumentOutOfRangeException) {}
-
- if (!isAmbiguousLocalDst) {
- try {
- ambiguousStartModified = ambiguousStart.AddYears(-1);
- ambiguousEndModified = ambiguousEnd.AddYears(-1);
- isAmbiguousLocalDst = (time >= ambiguousStart && time < ambiguousEnd);
- }
- catch (ArgumentOutOfRangeException) {}
- }
-
- }
- }
-
- return isDst;
- }
-
-
- static private Boolean CheckIsDst(DateTime startTime, DateTime time, DateTime endTime) {
- Boolean isDst;
-
- int startTimeYear = startTime.Year;
- int endTimeYear = endTime.Year;
-
- if (startTimeYear != endTimeYear) {
- endTime = endTime.AddYears(startTimeYear - endTimeYear);
- }
-
- int timeYear = time.Year;
-
- if (startTimeYear != timeYear) {
- time = time.AddYears(startTimeYear - timeYear);
- }
-
- if (startTime > endTime) {
- // In southern hemisphere, the daylight saving time starts later in the year, and ends in the beginning of next year.
- // Note, the summer in the southern hemisphere begins late in the year.
- isDst = (time < endTime || time >= startTime);
- }
- else {
- // In northern hemisphere, the daylight saving time starts in the middle of the year.
- isDst = (time >= startTime && time < endTime);
- }
- return isDst;
- }
-
- //
- // GetDaylightTime -
- //
- // Helper function that returns a DaylightTime from a year and AdjustmentRule
- //
- static private DaylightTime GetDaylightTime(Int32 year, AdjustmentRule rule) {
- TimeSpan delta = rule.DaylightDelta;
- DateTime startTime = TransitionTimeToDateTime(year, rule.DaylightTransitionStart);
- DateTime endTime = TransitionTimeToDateTime(year, rule.DaylightTransitionEnd);
- return new DaylightTime(startTime, endTime, delta);
- }
-
- //
- // TransitionTimeToDateTime -
- //
- // Helper function that converts a year and TransitionTime into a DateTime
- //
- static private DateTime TransitionTimeToDateTime(Int32 year, TransitionTime transitionTime) {
- DateTime value;
- DateTime timeOfDay = transitionTime.TimeOfDay;
-
- if (transitionTime.IsFixedDateRule) {
- // create a DateTime from the passed in year and the properties on the transitionTime
-
- // if the day is out of range for the month then use the last day of the month
- Int32 day = DateTime.DaysInMonth(year, transitionTime.Month);
-
- value = new DateTime(year, transitionTime.Month, (day < transitionTime.Day) ? day : transitionTime.Day,
- timeOfDay.Hour, timeOfDay.Minute, timeOfDay.Second, timeOfDay.Millisecond);
- }
- else {
- if (transitionTime.Week <= 4) {
- //
- // Get the (transitionTime.Week)th Sunday.
- //
- value = new DateTime(year, transitionTime.Month, 1,
- timeOfDay.Hour, timeOfDay.Minute, timeOfDay.Second, timeOfDay.Millisecond);
-
- int dayOfWeek = (int)value.DayOfWeek;
- int delta = (int)transitionTime.DayOfWeek - dayOfWeek;
- if (delta < 0) {
- delta += 7;
- }
- delta += 7 * (transitionTime.Week - 1);
-
- if (delta > 0) {
- value = value.AddDays(delta);
- }
- }
- else {
- //
- // If TransitionWeek is greater than 4, we will get the last week.
- //
- Int32 daysInMonth = DateTime.DaysInMonth(year, transitionTime.Month);
- value = new DateTime(year, transitionTime.Month, daysInMonth,
- timeOfDay.Hour, timeOfDay.Minute, timeOfDay.Second, timeOfDay.Millisecond);
-
- // This is the day of week for the last day of the month.
- int dayOfWeek = (int)value.DayOfWeek;
- int delta = dayOfWeek - (int)transitionTime.DayOfWeek;
- if (delta < 0) {
- delta += 7;
- }
-
- if (delta > 0) {
- value = value.AddDays(-delta);
- }
- }
- }
- return value;
- }
-
- //
- // IsInvalidTime -
- //
- // returns true when dateTime falls into a "hole in time".
- //
- public Boolean IsInvalidTime(DateTime dateTime) {
- Boolean isInvalid = false;
-
- if ( (dateTime.Kind == DateTimeKind.Unspecified)
- || (dateTime.Kind == DateTimeKind.Local && this == Local) ) {
-
- // only check Unspecified and (Local when this TimeZoneInfo instance is Local)
- AdjustmentRule rule = GetAdjustmentRuleForTime(dateTime);
-
-
- if (rule != null) {
- DaylightTime daylightTime = GetDaylightTime(dateTime.Year, rule);
- isInvalid = GetIsInvalidTime(dateTime, rule, daylightTime);
- }
- else {
- isInvalid = false;
- }
- }
-
- return isInvalid;
- }
-
- //
- // GetIsInvalidTime -
- //
- // Helper function that checks if a given DateTime is in an invalid time ("time hole")
- // A "time hole" occurs at a DST transition point when time jumps forward;
- // For example, in Pacific Standard Time on Sunday, April 2, 2006 time jumps from
- // 1:59:59.9999999 to 3AM. The time range 2AM to 2:59:59.9999999AM is the "time hole".
- // A "time hole" is not limited to only occurring at the start of DST, and may occur at
- // the end of DST as well.
- //
- static private Boolean GetIsInvalidTime(DateTime time, AdjustmentRule rule, DaylightTime daylightTime) {
- Boolean isInvalid = false;
- if (rule == null || rule.DaylightDelta == TimeSpan.Zero) {
- return isInvalid;
- }
-
- DateTime startInvalidTime;
- DateTime endInvalidTime;
-
- // if at DST start we transition forward in time then there is an ambiguous time range at the DST end
- if (rule.DaylightDelta < TimeSpan.Zero) {
- startInvalidTime = daylightTime.End;
- endInvalidTime = daylightTime.End - rule.DaylightDelta; /* */
- }
- else {
- startInvalidTime = daylightTime.Start;
- endInvalidTime = daylightTime.Start + rule.DaylightDelta; /* */
- }
-
- isInvalid = (time >= startInvalidTime && time < endInvalidTime);
-
- if (!isInvalid && startInvalidTime.Year != endInvalidTime.Year) {
- // there exists an extreme corner case where the start or end period is on a year boundary and
- // because of this the comparison above might have been performed for a year-early or a year-later
- // than it should have been.
- DateTime startModifiedInvalidTime;
- DateTime endModifiedInvalidTime;
- try {
- startModifiedInvalidTime = startInvalidTime.AddYears(1);
- endModifiedInvalidTime = endInvalidTime.AddYears(1);
- isInvalid = (time >= startModifiedInvalidTime && time < endModifiedInvalidTime);
- }
- catch (ArgumentOutOfRangeException) {}
-
- if (!isInvalid) {
- try {
- startModifiedInvalidTime = startInvalidTime.AddYears(-1);
- endModifiedInvalidTime = endInvalidTime.AddYears(-1);
- isInvalid = (time >= startModifiedInvalidTime && time < endModifiedInvalidTime);
- }
- catch (ArgumentOutOfRangeException) {}
- }
- }
- return isInvalid;
- }
+ // Shortcut for TimeZoneInfo.Local.GetUtcOffset
+ internal static TimeSpan GetLocalUtcOffset(DateTime dateTime, TimeZoneInfoOptions flags)
+ {
+ bool dst;
+ return Local.GetUtcOffset (dateTime, out dst);
+ }
+
+ internal TimeSpan GetUtcOffset(DateTime dateTime, TimeZoneInfoOptions flags)
+ {
+ bool dst;
+ return GetUtcOffset (dateTime, out dst);
+ }
+
+ static internal TimeSpan GetUtcOffsetFromUtc (DateTime time, TimeZoneInfo zone, out Boolean isDaylightSavings, out Boolean isAmbiguousLocalDst)
+ {
+ isDaylightSavings = false;
+ isAmbiguousLocalDst = false;
+ TimeSpan baseOffset = zone.BaseUtcOffset;
+
+ if (zone.IsAmbiguousTime (time)) {
+ isAmbiguousLocalDst = true;
+ return baseOffset;
+ }
+
+ return zone.GetUtcOffset (time, out isDaylightSavings);
+ }
#endregion
}
projects / mono.git / commitdiff