def deltet(epoch, eptype):
    """
    Return the value of Delta ET (ET-UTC) for an input epoch.

    http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/deltet_c.html

    :param epoch: Input epoch (seconds past J2000).
    :type epoch: float
    :param eptype: Type of input epoch ("UTC" or "ET").
    :type eptype: str
    :return: Delta ET (ET-UTC) at input epoch.
    :rtype: float
    """
    epoch = ctypes.c_double(epoch)
    eptype = stypes.stringToCharP(eptype)
    delta = ctypes.c_double()
    libspice.deltet_c(epoch, eptype, ctypes.byref(delta))
    return delta.value
Return the value of Delta ET (ET-UTC) for an input epoch.

    http://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/deltet_c.html

    :param epoch: Input epoch (seconds past J2000).
    :type epoch: float
    :param eptype: Type of input epoch ("UTC" or "ET").
    :type eptype: str
    :return: Delta ET (ET-UTC) at input epoch.
    :rtype: float