'Convert from the Excel JD back to a date'

def from_julian(self, value=0):

    if (self.excel_base_date == self.CALENDAR_WINDOWS_1900):
        excel_base_date = 25569
        if (value < 60):
            excel_base_date -= 1
        elif (value == 60):
            msg = 'Error:    Excel    believes    1900    was    a    leap    year'
            raise ValueError(msg)
    else:
        raise NotImplementedError('Mac    dates    are    not    yet    supported.')
    if (value >= 1):
        utc_days = (value - excel_base_date)
        return (EPOCH + datetime.timedelta(days=utc_days))
    elif (value >= 0):
        hours = floor((value * 24))
        mins = (floor(((value * 24) * 60)) - floor((hours * 60)))
        secs = ((floor((((value * 24) * 60) * 60)) - floor(((hours * 60) * 60))) - floor((mins * 60)))
        return datetime.time(int(hours), int(mins), int(secs))
    else:
        msg = ('Negative    dates    (%s)    are    not    supported' % value)
        raise ValueError(msg)
