OBSERVING PERIODS- 2023
      (UT dates. Lick PST=UT-8h   Keck HST=UT-10h)
      --------------------------------------------
            DURATION       RUN           MOON
           FQ+1 to LQ      bright     PHASE  DATE
           LQ+1 to FQ      dark              (UT)
     ---------------------------------------------
     2022 Dec 31-Jan 15    BRIGHT    FULL   Jan 06
     2023 Jan 16-Jan 28    DARK      NEW    Jan 21
     2023 Jan 29-Feb 13    BRIGHT    FULL   Feb 05
     2023 Feb 14-Feb 27    DARK      NEW    Feb 20
     2023 Feb 28-Mar 15    BRIGHT    FULL   Mar 07
     2023 Mar 16-Mar 29    DARK      NEW    Mar 21
     2023 Mar 30-Apr 13    BRIGHT    FULL   Apr 06
     2023 Apr 14-Apr 27    DARK      NEW    Apr 20
     2023 Apr 28-May 12    BRIGHT    FULL   May 05
     2023 May 13-May 27    DARK      NEW    May 19
     2023 May 28-Jun 10    BRIGHT    FULL   Jun 04
     2023 Jun 11-Jun 26    DARK      NEW    Jun 18
     2023 Jun 27-Jul 10    BRIGHT    FULL   Jul 03
     2023 Jul 11-Jul 25    DARK      NEW    Jul 17
     2023 Jul 26-Aug 08    BRIGHT    FULL   Aug 01
     2023 Aug 09-Aug 24    DARK      NEW    Aug 16
     2023 Aug 25-Sep 06    BRIGHT    FULL   Aug 31
     2023 Sep 07-Sep 22    DARK      NEW    Sep 15
     2023 Sep 23-Oct 06    BRIGHT    FULL   Sep 29
     2023 Oct 07-Oct 22    DARK      NEW    Oct 14
     2023 Oct 23-Nov 05    BRIGHT    FULL   Oct 28
     2023 Nov 06-Nov 20    DARK      NEW    Nov 13
     2023 Nov 21-Dec 05    BRIGHT    FULL   Nov 27
     2023 Dec 06-Dec 19    DARK      NEW    Dec 12
     2023 Dec 20-Jan 04    BRIGHT    FULL   Dec 27
     ---------------------------------------------