@staticmethod
def _parse_time(time_index):
    """
        Convert UTC datetime index into:
        - Days since Greenwhich Noon
        - Zulu hour

        Parameters
        ----------
        time_index : pandas.DatetimeIndex
            Datetime stamps of interest

        Returns
        -------
        n : ndarray
            Days since Greenwich Noon
        zulu : ndarray
            Decimal hour in UTC (Zulu Hour)
        """
    n = (time_index.to_julian_date() - 2451545).values
    zulu = (time_index.hour + time_index.minute / 60).values
    return n, zulu
