private static Func <ExactDateInfo, ExactDateInfo> NextTickDateForYears(
Duration tickDuration)
{
var oneYear = Duration.Zero.AddYears(1);
var eraStart = ExactDateInfo.AnnoDomini(1, 1, 1, 0);
return(prevTickDate =>
{
if (tickDuration > oneYear &&
prevTickDate == eraStart)
{
return prevTickDate + tickDuration - oneYear;
}
return prevTickDate + tickDuration;
});
}
/// <summary>
/// Gets date corresponding to this duration
/// after Christ birth.
/// </summary>
public ExactDateInfo GetDateAfterChristBirth()
{
var duration = _hours;
var era = duration >= 0
? Era.AnnoDomini
: Era.BeforeChrist;
if (era == Era.AnnoDomini)
{
var years = duration / HoursInYear;
duration -= HoursInYear * years;
years += 1;
var months = Convert.ToInt32(duration / HoursInMonth);
duration -= HoursInMonth * months;
months += 1;
var days = Convert.ToInt32(duration / HoursInDay);
duration -= HoursInDay * days;
days += 1;
FixDate(ref years, ref months, ref days);
var hours = Convert.ToInt32(duration);
return(ExactDateInfo.AnnoDomini(years, months, days, hours));
}
else
{
var years = duration / HoursInYear;
if (duration != years * HoursInYear)
{
years -= 1;
}
duration -= HoursInYear * years;
years = -years;
var months = Convert.ToInt32(duration / HoursInMonth);
duration -= HoursInMonth * months;
months += 1;
var days = Convert.ToInt32(duration / HoursInDay);
duration -= HoursInDay * days;
days += 1;
var hours = Convert.ToInt32(duration);
return(ExactDateInfo.BeforeChrist(years, months, days, hours));
}
}