Which days are free from work :)?

HI ALL,

Today i have got some challenge to do. I would like to ask You guys about help :).

I would like to use activity: “Invoke Code” where in_parameter is date and out_parameter is bool.

I need to change this code to usefull code which i can use in activity.

“public static class HolidayCalculator
{
public static bool IsHoliday (this DateTime Day)
{
if (Day.DayOfWeek == DayOfWeek.Sunday) return true;
if (Day.Month == 1 && Day.Day == 1) return true; // Nowy Rok
if (Day.Month == 5 && Day.Day == 1) return true; // 1 maja
if (Day.Month == 5 && Day.Day == 3) return true; // 3 maja
if (Day.Month == 8 && Day.Day == 15) return true; // Wniebowzięcie Najświętszej Marii Panny, Święto Wojska Polskiego
if (Day.Month == 11 && Day.Day == 1) return true; // Dzień Wszystkich Świętych
if (Day.Month == 11 && Day.Day == 11) return true; // Dzień Niepodległości
if (Day.Month == 12 && Day.Day == 25) return true; // Boże Narodzenie
if (Day.Month == 12 && Day.Day == 26) return true; // Boże Narodzenie
int a = Day.Year % 19;
int b = Day.Year % 4;
int c = Day.Year % 7;
int d = (a * 19 + 24) % 30;
int e = (2 * b + 4 * c + 6 * d + 5) % 7;
if (d == 29 && e == 6) d -= 7;
if (d == 28 && e == 6 && a > 10) d -= 7;
DateTime Easter = new DateTime (Day.Year, 3, 22).AddDays (d + e);
if (Day.AddDays (-1) == Easter)
return true; // Wielkanoc (poniedziałek)
if (Day.AddDays (-60) == Easter)
return true; // Boże Ciało
return false;
}
}”

Many thanks for help.
@fudi5