
# Listing 4
# This function computes the gregorian date from the julian date - $1.  
# Returns a date string in the form: MONTH DAY YEAR
# See URL: 
# http://aa.usno.navy.mil/faq/docs/JD_Formula.html 
# for more information
get_greg_from_JD()
{
typeset -i L
typeset -i N
typeset -i I
typeset -i J
typeset -i DAY
typeset -i MON
typeset -i YR

L=$(($1+68569)) # $1 is the julian date
N=$((4*L/146097))
L=$((L-(146097*N+3)/4))
I=$((4000*(L+1)/1461001))
L=$((L-1461*I/4+31))
J=$((80*L/2447))
DAY=$((L-2447*J/80)) 
L=$((J/11))
MON=$((J+2-12*L))
YR=$((100*(N-49)+I+L))

echo $MON $DAY $YR
} # end Listing 4
