*** Almanac for the currently specified date ***:
Almanac for Roque de los Muchachos:
long.   1 11 31 (h.m.s) W, lat.  28 45.5 (d.m), elev.  2326 m
pseudo-Greenwich Daylight Savings Time assumed from 2 AM on
2000 Mar 26 to 2 AM on 2000 Sep 24; standard zone =   0 hrs W

For the night of: Sat, 2000 May 20 ---> Sun, 2000 May 21
Local midnight = 2000 May 20, 23 hr UT, or JD 2451685.458
Local Mean Sidereal Time at midnight =  13 44 05.5

Sunset ( 2326 m horizon):   21 06 GDT; Sunrise:    7 09 GDT
Evening twilight:   22 29 GDT;  LMST at evening twilight:   12 13
Morning twilight:    5 47 GDT;  LMST at morning twilight:   19 32
12-degr twilight:  21 56 GDT -->   6 20 GDT; night center:    2 08 GDT

Moonrise:   22 53 GDT   
Moon at civil midnight: illuminated fraction 0.933
2.6 days after full moon, RA and dec:  18 00 55, -21 41.7

The sun is down for 10.1 hr;  7.3 hr from eve->morn 18 deg twilight.
 0.4 dark hours after end of twilight and before moonrise.