public OffsetAndRule GetOneYearLocalFromUtc(int year)
{
OffsetAndRule? oneYearLocFromUtc = _oneYearLocalFromUtc;
if (oneYearLocFromUtc == null || oneYearLocFromUtc.Year != year)
{
TimeZoneInfo currentYear = GetCurrentOneYearLocal();
AdjustmentRule? rule = currentYear._adjustmentRules == null ? null : currentYear._adjustmentRules[0];
oneYearLocFromUtc = new OffsetAndRule(year, currentYear.BaseUtcOffset, rule);
_oneYearLocalFromUtc = oneYearLocFromUtc;
}
return oneYearLocFromUtc;
}
// DateTime.Now fast path that avoids allocating an historically accurate TimeZoneInfo.Local and just creates a 1-year (current year) accurate time zone
internal static TimeSpan GetDateTimeNowUtcOffsetFromUtc(DateTime time, out bool isAmbiguousLocalDst)
{
bool isDaylightSavings = false;
isAmbiguousLocalDst = false;
TimeSpan baseOffset;
int timeYear = time.Year;
OffsetAndRule match = s_cachedData.GetOneYearLocalFromUtc(timeYear);
baseOffset = match.Offset;
if (match.Rule != null)
{
baseOffset = baseOffset + match.Rule.BaseUtcOffsetDelta;
if (match.Rule.HasDaylightSaving)
{
isDaylightSavings = GetIsDaylightSavingsFromUtc(time, timeYear, match.Offset, match.Rule, out isAmbiguousLocalDst, Local);
baseOffset += (isDaylightSavings ? match.Rule.DaylightDelta : TimeSpan.Zero /* FUTURE: rule.StandardDelta */);
}
}
return(baseOffset);
}
