codice:
public class Festivity
{
private class CalendarConstants
{
public int? minDate { get; set; }
public int maxDate { get; set; }
public int x { get; set; }
public int y { get; set; }
}
private static IEnumerable<CalendarConstants> Costanti = new List<CalendarConstants>()
{
new CalendarConstants() { minDate = null , maxDate = 1582, x = 15, y= 6 },
new CalendarConstants() { minDate = 1583 , maxDate = 1699, x = 22, y= 2 },
new CalendarConstants() { minDate = 1700 , maxDate = 1799, x = 23, y= 3 },
new CalendarConstants() { minDate = 1800 , maxDate = 1899, x = 23, y= 4 },
new CalendarConstants() { minDate = 1900 , maxDate = 2099, x = 24, y= 5 },
new CalendarConstants() { minDate = 2100 , maxDate = 2199, x = 24, y= 6 },
new CalendarConstants() { minDate = 2200 , maxDate = 2299, x = 25, y= 7 },
new CalendarConstants() { minDate = 2300 , maxDate = 2399, x = 26, y= 1 },
new CalendarConstants() { minDate = 2400 , maxDate = 2499, x = 25, y= 1 }
};
public static DateTime? GetEasterDate(int year)
{
var constant = Costanti.First(cx =>
(!cx.minDate.HasValue || year >= cx.minDate.Value) &&
(year <= cx.maxDate));
var x = constant.x;
var y = constant.y;
var a = year % 19;
var b = year % 4;
var c = year % 7;
var d = (19 * a + x) % 30;
var e = (2 * b + 4 * c + 6 * d + y) % 7;
var sum = 22 + d + e;
if (sum <= 31)
{
return new DateTime(year, 3, sum);
}
else if (((sum - 31) != 26 && (sum - 31) != 25) ||
((sum - 31) == 25 && (d != 28 || a <= 10)))
{
return new DateTime(year, 4, sum - 31);
}
else if ((sum - 31) == 25 && d == 28 && a > 10)
{
return new DateTime(year, 4, 18);
}
else
{
return new DateTime(year, 4, 19);
}
}
public static Dictionary<string, DateTime> FestivityInYear(int year)
{
var rtn = new Dictionary<string, DateTime>();
rtn.Add("Primo dell'anno", new DateTime(year, 1, 1));
rtn.Add("Epifania", new DateTime(year, 1, 6));
rtn.Add("Festa della Liberazione", new DateTime(year, 4, 25));
rtn.Add("Festa del Lavoro", new DateTime(year, 5, 1));
rtn.Add("Fondazione della Repubblica", new DateTime(year, 6, 2));
rtn.Add("Assunzione Beata Vergine Maria (Ferragosto)", new DateTime(year, 8, 15));
rtn.Add("Ognissanti", new DateTime(year, 11, 1));
rtn.Add("Immacolata Concezione", new DateTime(year, 12, 8));
rtn.Add("Natale", new DateTime(year, 1, 6));
rtn.Add("S.Stefano", new DateTime(year, 1, 6));
rtn.Add("Pasqua", ((DateTime)GetEasterDate(year)));
rtn.Add("Pasquetta", ((DateTime)GetEasterDate(year)).AddDays(1));
return rtn;
}
public static bool IsLeapYear(int year)
{
return DateTime.IsLeapYear(year);
}
}