dateDiff.py

# Python3 program two find number of
# days between two given dates

# A date has day 'd', month 'm' and year 'y'


class Date:
	def __init__(self, d, m, y):
		self.d = d
		self.m = m
		self.y = y


# To store number of days in all months from
# January to Dec.
monthDays = [31, 28, 31, 30, 31, 30,
			31, 31, 30, 31, 30, 31]

# This function counts number of leap years
# before the given date


def countLeapYears(d):

	years = d.y

	# Check if the current year needs to be considered
	# for the count of leap years or not
	if (d.m <= 2):
		years -= 1

	# An year is a leap year if it is a multiple of 4,
	# multiple of 400 and not a multiple of 100.
	return int(years / 4) - int(years / 100) + int(years / 400)


# This function returns number of days between two
# given dates
def getDifference(dt1, dt2):

	# COUNT TOTAL NUMBER OF DAYS BEFORE FIRST DATE 'dt1'

	# initialize count using years and day
	n1 = dt1.y * 365 + dt1.d

	# Add days for months in given date
	for i in range(0, dt1.m - 1):
		n1 += monthDays[i]

	# Since every leap year is of 366 days,
	# Add a day for every leap year
	n1 += countLeapYears(dt1)

	# SIMILARLY, COUNT TOTAL NUMBER OF DAYS BEFORE 'dt2'

	n2 = dt2.y * 365 + dt2.d
	for i in range(0, dt2.m - 1):
		n2 += monthDays[i]
	n2 += countLeapYears(dt2)

	# return difference between two counts
	return (n2 - n1)


# Driver program
dt1 = Date(13, 12, 2018)
dt2 = Date(25, 2, 2019)

print(getDifference(dt1, dt2), "days")