Equation for the great jupiter saturn perturbation ky = year(ctod(mdate))+3102 a = ky-4660 b = mod(a,918) c = b 12/918 e = c30

do case
case e < 90 f = e case e > 90 .and. e < 180 f = 180-e case e > 180 .and. e < 270 f = e -180 case e > 270 .and. e < 360
f = 360 -e
endcase

SBJ = SIN(DTOR(F))*10000