Visibility of Luna and Lunar Crescent

Now orc n6ds ro c@t 6. nub.r of diys .laps.d si@ the Julid DaL
epoch (Jeulry l, 4712) iill Ihc .nd of th. PEviou yc& .rd lhe trmb€r of dltr
€laled flom ln. n61 d.y of rh. PEviou yd till the cnd of lhe c|lml monlh
Meu @dider this sMbl ianing fom ys -4716 dD( adds addilional davs
thal @ balmed by subt@lion of lh. co6t ni 1524.5.
JD=\NTQ65.2t(UW+ 17 16)+ tl]/r(30.600t (uMM+ 1))+ UDD+ B-l 524 5
+ (u HH + (UMIN + USEq60)/60)/21
(2.4.r)
ln both th. lh.orics VSOP8? tnd ELP2000 lhe €Poch is the J2000 0
@ftsponding ro rhe Julie Dsr.2451545 theEfot one tin lly c.t5 the lin€
JD 245t545 Ar
16525 1155760000
(242)
Notc rtEt in rhc l6t st@ lh. lid l.B on 0E lighl hfld side is the nmbd of
lulie entude elap*d sine 12000.0 ad th. s@sd l@ is for At which is @allv
siven in mobd of.eonds od h.rc w. nccd to @nved n i o nmb.r of c€ntuies (lio
ELP &d Millemia for vsoP) due to which il hN lo be divided by the nunbq of s6onds
in a Juli$ c€nrury ifor ELP md Julim Mill.inia fot VSOP).
lf and when ttie dynmical tim. of d cv.nt is *rom we need io @hv.n rl b
U.ivesal dd Lhen into Local Zon. tim.. Thc dylmical tihe is oblain d s the nmbet
of Julie cenluries sin@ J2000.0 e that rhc Julisn dare of tbe evmt cm b€ calculated 6:
48