*** 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
1998 Mar 29 to 2 AM on 1998 Sep 27; standard zone =   0 hrs W

For the night of: Fri, 1998 May 22 ---> Sat, 1998 May 23
Local midnight = 1998 May 22, 23 hr UT, or JD 2450956.458
Local Mean Sidereal Time at midnight =  13 49 56.7

Sunset ( 2326 m horizon):   21 07 GDT; Sunrise:    7 09 GDT
Evening twilight:   22 30 GDT;  LMST at evening twilight:   12 20
Morning twilight:    5 46 GDT;  LMST at morning twilight:   19 37
12-degr twilight:  21 57 GDT -->   6 19 GDT; night center:    2 08 GDT

Moonset :   17 37 GDT   Moonrise:    5 28 GDT   
Moon at civil midnight: illuminated fraction 0.117
2.9 days before new moon, RA and dec:   1 26 41,   4 39.6

The sun is down for 10.0 hr;  7.3 hr from eve->morn 18 deg twilight.
 7.0 dark hours after end of twilight and before moonrise.