void CompareTimeZone()
{
if (dawnTime < time && time < dayTime)
{
timezone = TIMEZONE.DAWN;
}
else if (dayTime < time && time < nightTime)
{
timezone = TIMEZONE.DAY;
}
else if (nightTime < time)
{
timezone = TIMEZONE.NIGHT;
}
}
//=====================================================================
/// <summary>
/// This is used to load the VCalendar.TimeZones collection with time zone information from the registry
/// </summary>
public static void LoadTimeZoneInfo()
{
string keyName, display, standardDesc, dstDesc;
TIMEZONE tz;
VCalendar.TimeZones.Clear();
// To keep things simple, we'll load the time zone data from the settings available in the registry.
// We could take it a step further and load it from something like a copy of the Olson time zone
// database but I haven't been that ambitious yet.
if (Environment.OSVersion.Platform == PlatformID.Win32NT)
{
keyName = @"SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones";
}
else
{
keyName = @"SOFTWARE\Microsoft\Windows\CurrentVersion\Time Zones";
}
using (var rk = Registry.LocalMachine.OpenSubKey(keyName))
{
foreach (string s in rk.GetSubKeyNames())
{
using (var rsk = rk.OpenSubKey(s))
{
display = (string)rsk.GetValue("Display");
standardDesc = (string)rsk.GetValue("Std");
dstDesc = (string)rsk.GetValue("Dlt");
tz = TIMEZONE.FromRegistry(rsk.GetValue("TZI"));
}
// Create the time zone object
VTimeZone vtz = new VTimeZone();
vtz.TimeZoneId.Value = display;
ObservanceRule or = vtz.ObservanceRules.Add(ObservanceRuleType.Standard);
or.OffsetFrom.TimeSpanValue = TimeSpan.FromMinutes(tz.nBias + tz.nDaylightBias).Negate();
or.OffsetTo.TimeSpanValue = TimeSpan.FromMinutes(tz.nBias + tz.nStandardBias).Negate();
or.TimeZoneNames.Add(standardDesc);
// If the standard date month is zero, it doesn't use standard time. Assume 01/01/1970 and
// set it up to return the offset.
if (tz.standardDate.wMonth == 0)
{
or.StartDateTime.DateTimeValue = new DateTime(1970, 1, 1);
}
else
{
// If year is zero, its a recurrence. If not zero, it's a fixed date.
if (tz.standardDate.wYear == 0)
{
or.StartDateTime.DateTimeValue = tz.standardDate.ToDateTime(1970);
RRuleProperty rrule = new RRuleProperty();
rrule.Recurrence.RecurYearly(
(tz.standardDate.wDay > 4) ? DayOccurrence.Last : (DayOccurrence)tz.standardDate.wDay,
tz.standardDate.DayOfWeek(), tz.standardDate.wMonth, 1);
or.RecurrenceRules.Add(rrule);
}
else
{
or.StartDateTime.DateTimeValue = tz.standardDate.ToDateTime();
or.RecurDates.Add(or.StartDateTime.DateTimeValue);
}
}
// If the daylight month is zero, it doesn't use DST. The standard rule will handle
// everything.
if (tz.daylightDate.wMonth != 0)
{
or = vtz.ObservanceRules.Add(ObservanceRuleType.Daylight);
or.OffsetFrom.TimeSpanValue = TimeSpan.FromMinutes(tz.nBias + tz.nStandardBias).Negate();
or.OffsetTo.TimeSpanValue = TimeSpan.FromMinutes(tz.nBias + tz.nDaylightBias).Negate();
or.TimeZoneNames.Add(dstDesc);
// If year is zero, its a recurrence. If not zero, it's a fixed date.
if (tz.daylightDate.wYear == 0)
{
or.StartDateTime.DateTimeValue = tz.daylightDate.ToDateTime(1970);
RRuleProperty rrule = new RRuleProperty();
rrule.Recurrence.RecurYearly(
(tz.daylightDate.wDay > 4) ? DayOccurrence.Last : (DayOccurrence)tz.daylightDate.wDay,
tz.daylightDate.DayOfWeek(), tz.daylightDate.wMonth, 1);
or.RecurrenceRules.Add(rrule);
}
else
{
or.StartDateTime.DateTimeValue = tz.daylightDate.ToDateTime();
or.RecurDates.Add(or.StartDateTime.DateTimeValue);
}
}
VCalendar.TimeZones.Add(vtz);
}
}
// Put the time zones in sorted order
VCalendar.TimeZones.Sort(true);
}
