Primitive time tally tool

timetally.py

import time

def get_day_minutes(t):
	s = time.strptime(t, '%H:%M')
	return s.tm_hour * 60 + s.tm_min

def calc_duration(start_time, stop_time):
	'Returns how many minutes have passed between two times expressed as HH:MM'
	'Wraps around for midnight'
	'Does not track DST'
	duration = get_day_minutes(stop_time) - get_day_minutes(start_time)
	
	if duration < 0:	#midnight wrap around
		return duration + 24 * 60
	return duration


def fmt_minutes(minutes):
	'Formats a number of minutes as HH:MM'
	return f'{minutes // 60}:{str(minutes % 60).zfill(2)}'


print("EOF (Ctrl+D) when done, SIGINT (Ctrl+C) to restart input from last valid input")
totals = dict()

while True:
	try:
		print('From:', end=' '); start_time = input()
		print('To:', end=' '); stop_time = input()
		print('Activity:', end=' '); activity = input()
	except EOFError:
		break
	except KeyboardInterrupt:	
		print("\nAborted input, try again")
		continue

	try:
		duration = calc_duration(start_time, stop_time)
	except ValueError as e:
		print(f'\nInvalid input, try again ({e})')
		continue

	print()
	print(f'Duration: {fmt_minutes(duration)}')
	print()

	totals[activity] = totals.get(activity, 0) + duration

print()
print('-'*50)
print('Totals')
print('-'*50)
for activity, duration in totals.items():
	print(f'\t{activity}\t{fmt_minutes(duration)}')