I'm currently developing a program to detect the number of Sundays that fall on the first day of a month between two specified dates.
My goal is to achieve this without relying on datetime functions.
Interestingly, my calculations yield 173 when the expected count should be 171.
#Determining how many Sundays occur on the first day of each month in the twentieth century (1 Jan 1901 to 31 Dec 2000).
days_of_week = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']
dict_months = {"January": 31, "February": 28, "March": 31, "April": 30, "May": 31, "June": 30, "July": 31, "August": 31, "September": 30, "October": 31, "November": 30, "December": 31}
count = 0
weekday_index = -1
for year in range(1900,2001):
for month in dict_months:
#handling february
if month == "February":
#accounting for leap years
if year % 4 == 0:
#century years are leap years only if divisible by 400
if year % 100 == 0 and year % 400 != 0:
dict_months[month] = 28
else:
dict_months["February"] = 29
else:
dict_months["February"] = 28
for day in range(1, dict_months[month]+1):
weekday_index += 1
weekday = days_of_week[weekday_index]
#checking for Sundays
if weekday == 'Sunday':
weekday_index = -1
if day == 1:
# print(f"{month} {day} {year}")
count += 1
print(count)