def gauss_easter(year: int) -> datetime:
    metonic_cycle = year % 19
    julian_leap_year = year % 4
    non_leap_year = year % 7
    leap_day_inhibits = math.floor(year / 100)
    lunar_orbit_correction = math.floor((13 + 8 * leap_day_inhibits) / 25)
    leap_day_reinstall_number = leap_day_inhibits / 4
    secular_moon_shift = (
        15 - lunar_orbit_correction + leap_day_inhibits - leap_day_reinstall_number
    ) % 30
    century_starting_point = (4 + leap_day_inhibits - leap_day_reinstall_number) % 7

    # days to be added to March 21
    days_to_add = (19 * metonic_cycle + secular_moon_shift) % 30

    # PHM -> Paschal Full Moon
    days_from_phm_to_sunday = (
        2 * julian_leap_year
        + 4 * non_leap_year
        + 6 * days_to_add
        + century_starting_point
    ) % 7

    if days_to_add == 29 and days_from_phm_to_sunday == 6:
        return datetime(year, 4, 19)
    elif days_to_add == 28 and days_from_phm_to_sunday == 6:
        return datetime(year, 4, 18)
    else:
        return datetime(year, 3, 22) + timedelta(
            days=int(days_to_add + days_from_phm_to_sunday)
        )