day-of-programmer.py

def is_leap_year(year):
    if year < 1918:
        return year%4 == 0
    elif year > 1918:  
        return (year%400==0) or ((year%4==0) and (year%100 != 0))

def day_of_programmer(year):
    if year == 1918:
        return f"26.09.{year}"
    else:   
        if is_leap_year(year):
            return f"12.09.{year}"
        else:
            return f"13.09.{year}"

# Test
print(day_of_programmer(2100))