YALO Observing Calendars

The YALO Observing calendars give the following data for each observing day of a given month:

Local times of:
1. Sunset
2. 12 & 18 Degree Twilight,
3. Moonrise & Moonset,
4. 18 & 12 Degree Dawn,
5. Sunrise
Sidereal times at Twilight, Midnight, & Dawn
Length of the night (twilight to dawn)
Number of moonless hours ("dark") and the percent dark.
RA and Dec of the Moon at midnight.

In addition to daily information, the dates and times of the four principal moon phases are given for each month.

All local times are in Chilean Standard Time (CST) except as noted.

The date refers to the date of the start of the night, thus the calendar entry for 1999 July 4 refers to the night beginning at sunset on July 4 and ending with sunrise on July 5. This is the same "observing day" convention used for all YALO observatory record keeping.

The calendars were created using programs kindly provided by Dr. Arnold Klemola at Lick Observatory (klemola@ucolick.org).

Full-Year Calendars

Copies of a full year of YALO observing calendars are available as gzip-compressed ascii text files. Each are 28Kb and uncompress to ~100Kb.

Updated: 2001 January 16 [rwp/osu]