*** 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: Tue, 1998 May 26 ---> Wed, 1998 May 27
Local midnight = 1998 May 26, 23 hr UT, or JD 2450960.458
Local Mean Sidereal Time at midnight =  14 05 42.9

Sunset ( 2326 m horizon):   21 10 GDT; Sunrise:    7 07 GDT
Evening twilight:   22 33 GDT;  LMST at evening twilight:   12 39
Morning twilight:    5 43 GDT;  LMST at morning twilight:   19 50
12-degr twilight:  22 00 GDT -->   6 17 GDT; night center:    2 08 GDT

Moonset :   22 01 GDT   
Moon at civil midnight: illuminated fraction 0.019
1.1 days since new moon, RA and dec:   5 19 49,  17 41.2

The sun is down for 10.0 hr;  7.2 hr from eve->morn 18 deg twilight.
Dark all night (moon down from evening to morning twilight).