This form allows you to select astronomical calendars for Mount Hamilton. Three different calendars are available from this form (see also bright and dark run calendars). Two contain the following information in either nautical (12 degree) or astronomical (18 degree) versions respectively:

  • sunrise/sunset
  • 12 and 18 degree twilight and dawn
  • moonrise/moonset
  • sidereal times at twilight, midnight, dawn (nautical or astronomical versions)
  • length of whole night, dark hours, % dark (nautical or astonomical versions)

    The third calendar gives the times of new, full, and first and last quarter moons for each month. Moon phase calendars include an entire year on one page, the "month" selection is therefore ignored.

    The calendars were prepared by Dr. Arnold Klemola
    UCO/Lick Observatory, University of California, Santa Cruz, CA 95064