Znalezienie świętych ASP.NET
var publicHolidays = DateSystem.GetPublicHoliday(2018, CountryCode.DE);
Poised Parrot
var publicHolidays = DateSystem.GetPublicHoliday(2018, CountryCode.DE);
PM> install-package Nager.Date
var date = new DateTime(2018, 01, 01);
if (DateSystem.IsPublicHoliday(date, CountryCode.DE))
{
//Yes - New Year's Day
}