I want to find sunday between the month

// The year (1 through 9999).
// The month (1 through 12).
static int CountSundays(int year, int month)
{
	var firstDay = new DateTime(year,month , 1);

	var day29 = firstDay.AddDays(28);
	var day30 = firstDay.AddDays(29);
	var day31 = firstDay.AddDays(30);

	if ((day29.Month == month && day29.DayOfWeek == DayOfWeek.Sunday)
	|| (day30.Month == month && day30.DayOfWeek == DayOfWeek.Sunday)
	|| (day31.Month == month && day31.DayOfWeek == DayOfWeek.Sunday))
	{
		return 5;
	}
	else
	{
		return 4;
	}
}