def JD_to_LST(JDs, llong):
    """Returns LST [frac. of day] using:
        JD - [iterable] - values of Julian data
        llong - local longitude [+/-degrees].
    """

    LSTs = list()

    llong_h = llong / 15.

    for JD in list(JDs):

        D = JD - 2451545.0
        GMST = 18.697374558 + 24.06570982441908 * D
        GMST = GMST % 24

        if GMST < 0:
            GMST += 24.
        elif GMST >= 24.0:
            GMST -= 24.0

        LST = GMST + llong_h
        #convert to fraction of day
        LST = LST / 24.

        LSTs.append(LST)

    return LSTs