Return to Question

I have made a Python program to find the day of the week of an inputted date. I did not want to use the time or datetime module, like in this answer, as I found that a bit too easy. (I like to challenge myself)

I have made a Python program to find the day of the week of an inputted date. I did not want to use the time or datetime module, like in this answer, as I found that a bit too easy. (I like to challenge myself)

month_days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
day_names = ["Friday", "Saturday", "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday"]
SYEAR = 2016
SMONTH = 1
SDAY = 1
def is_leap_year(year):
 return year % 4 == 0
def calc_year(year):
 days = 0
 tyear = SYEAR
 while not tyear == year:
 if tyear < year:
 if is_leap_year(tyear):
 days += 366
 else:
 days += 365
 tyear += 1
 if tyear > year:
 if is_leap_year(tyear - 1):
 days -= 366
 else:
 days -= 365
 tyear -= 1
 return days
def calc_month(month, year):
 days = 0
 tmonth = SMONTH
 while not tmonth == month:
 if tmonth < month:
  if tmonth == 2 and is_leap_year(year):
 days += 1
 days += month_days[tmonth - 1]
 tmonth += 1
 return days
def calc_day(day):
 days = 0
 tday = SDAY
 while not tday == day:
 if tday < day:
  tday += 1
 days += 1
 return days
def find_day(date):
 total = calc_month(date[0], date[2]) + calc_day(date[1]) + calc_year(date[2])
 if total < 0:
 return day_names[total % -7]
 else:
 return day_names[total % 7]
def main():
 date = input("Enter a day like so <MM, DD, YYYY>: ").split()
 month = int(date[0])
 day = int(date[1])
 year = int(date[2])
 if month > 12 or month <= 0:
 print("Invalid month")
 elif day > month_days[month - 1] or day <= 0:
 if not (day == 29 and month == 2):
 print("Invalid day")
 else:
 print(find_day((month, day, year)))
if __name__ == "__main__":
 main()

month_days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
day_names = ["Friday", "Saturday", "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday"]
SYEAR = 2016
SMONTH = 1
SDAY = 1
def is_leap_year(year):
 if year % 4 == 0:
 if year % 100 == 0:
  if year % 400 == 0:
 return True
 else:
 return False
 else:
 return True
 
 return False
def calc_year(year):
 days = 0
 tyear = SYEAR
 while not tyear == year:
 if tyear < year:
 if is_leap_year(tyear):
 days += 366
 else:
 days += 365
 tyear += 1
 if tyear > year:
 if is_leap_year(tyear - 1):
 days -= 366
 else:
 days -= 365
 tyear -= 1
 return days
def calc_month(month, year):
 days = 0
 tmonth = SMONTH
 while not tmonth == month:
 if tmonth == 2 and is_leap_year(year):
 days += 1
 days += month_days[tmonth - 1]
 tmonth += 1
 return days
def calc_day(day):
 days = 0
 tday = SDAY
 while not tday == day:
 tday += 1
 days += 1
 return days
def find_day(date):
 total = calc_month(date[0], date[2]) + calc_day(date[1]) + calc_year(date[2])
 if total < 0:
 return day_names[total % -7]
 else:
 return day_names[total % 7]
def main():
 date = input("Enter a day like so <MM, DD, YYYY>: ").split()
 month = int(date[0])
 day = int(date[1])
 year = int(date[2])
 if month > 12 or month <= 0:
 print("Invalid month")
 elif day > month_days[month - 1] or day <= 0:
 if not (day == 29 and month == 2):
 print("Invalid day")
 else:
 print(find_day((month, day, year)))
if __name__ == "__main__":
 main()