Convert datetime from/to excel serial date

excel_datetime_converter.py

from datetime import datetime, time


def serial_to_datetime(serial):
    """ Convert excel serial date to :class:`datetime` """
    # 30/12/1899 used instead of 01/01/1900 in order to offset 2 days due to, serial counting & excel leap year bug
    dt = datetime.fromordinal(datetime(1899, 12, 30).toordinal() + int(serial))
    t = serial_to_time(serial)
    return dt.replace(hour=t.hour, minute=t.minute, second=t.second)


def datetime_to_serial(dt):
    """ Convert :class:`datetime` to excel serial date """
    # 30/12/1899 used instead of 01/01/1900 in order to offset 2 days due to, serial counting & excel leap year bug
    delta = dt - datetime(1899, 12, 30)
    return float(delta.days) + (float(delta.seconds) / 86400)


def serial_to_time(serial):
    """ Convert excel serial time to :class:`time` """
    h, r = divmod(serial % 1 * 24, 1)
    m, r = divmod(r * 60, 1)
    return time(hour=int(h), minute=int(m), second=int(r * 60))


def time_to_serial(t):
    """ Convert :class:`time` to excel serial time """
    return (t.hour / 24) + (t.minute / 1440) + (t.second / 86400)