from datetime import datetime


def PyTmYMDtoJD(year, month, day):
    """
    Convert year-month-day to julian day

    Parameters
    ----------
    year: int, year as integer
    month: int, month as integer
    day: int, day as integer

    Returns
    -------
    int, julian day number
    """

    tt = datetime.strptime('%04d-%02d-%02d' % (year, month, day), '%Y-%m-%d').timetuple()
    return tt.tm_yday