def mjd2met(mjd):
    """
    Converts Modified Julian Day in Mission Elapsed Time (MET, in seconds).
    Cf. http://fermi.gsfc.nasa.gov/ssc/data/analysis/documentation/Cicerone/Cicerone_Data/Time_in_ScienceTools.html
    to see how the time is handled in the Fermi Science Tools.

    Input:  time in MJD (fraction of a day)
    Output: time in MET (s)
    """
    MJDREFI = 51910.0
    MJDREFF = 7.428703703703703e-4
    return (24. * 60. * 60 * (mjd - MJDREFI - MJDREFF))