Example game datetime functions

game_clock.py

from typing import Literal, Dict

# Our lowest resolution is in hours.
HOUR_LENGTH = 1
DAY_LENGTH = 24
SEASON_LENGTH = DAY_LENGTH * 30
YEAR_LENGTH = SEASON_LENGTH * 4

TimeKey = Literal['year', 'season', 'day', 'hour']
# Could use a DataClass or a TypedDict, but that would be distracting to the point I'm trying to show
# which is how the math works and how this approach handles edge cases.
DateDict = Dict[TimeKey, int]


def time_delta(*, hours: int = 0, days: int = 0, seasons: int = 0, years: int = 0) -> int:
    """
    Return a value that represents the number of hours for however many hours, days, seasons, and years
    forward we wish to travel.
    """
    return sum([
        hours,
        days * DAY_LENGTH,
        seasons * SEASON_LENGTH,
        years * YEAR_LENGTH,
    ])


def break_down_time(time_value: int) -> DateDict:
    """
    Break time down into a dict of integer values.
    """
    resolved: Dict[TimeKey, int] = {}
    remainder = time_value
    key: TimeKey
    for key, divisor in [('year', YEAR_LENGTH), ('season', SEASON_LENGTH), ('day', DAY_LENGTH)]:
        resolved[key] = (remainder // divisor) + 1  # The date begins at year 1, Not year 0.
        remainder = remainder % divisor
    resolved['hour'] = remainder
    return resolved


def date_dict_to_string(date_dict: DateDict) -> str:
    """
    Given a current time value, return the resolved datetime.
    """
    # We can remove this if we decide to do military time.
    post_time_marker = 'AM'
    hours = date_dict['hour']
    if hours > 12:
        post_time_marker = 'PM'
        hours -= 12
    if hours == 0:
        # Midnight.
        hours = 12
    return f'Year {date_dict["year"]}, Season {date_dict["season"]}, Day {date_dict["day"]}, {hours} {post_time_marker}'


def timestamp_to_string(timestamp: int) -> str:
    """Given an integer timestamp, return the display string."""
    return date_dict_to_string(break_down_time(timestamp))


if __name__ == '__main__':
    current_time = 0
    print(timestamp_to_string(current_time))
    current_time += time_delta(hours=5, days=3, seasons=0, years=1)
    print(timestamp_to_string(current_time))
    current_time += time_delta(seasons=5)
    print(timestamp_to_string(current_time))
    current_time += time_delta(days=45, hours=12)
    print(timestamp_to_string(current_time))
    arbitrary_date = {'year': 1, 'season': 2, 'day': 5, 'hour': 3}
    print(date_dict_to_string({'hour': 3, 'day': 5, 'year': 1, 'season': 2}))
    # Turning a date dict back into an int is an exercise left to the reader, but time_delta is 90% of the way there
    # already.