Rosh Hashanah calculator

[manyone]

there is nothing religious about this post. i'm not jewish but i've always been fascinated by calendars and the formulas behind them. the hebrew calendar is special because its formula evolved from apparent astrological and seasonal observations throughout history and its current form involves a lot of mathematical operations to handle all the various rules and exceptions that have developed over the years. i will not claim to understand the reasoning for the formulas. luckily, somebody has already written exclusively about the calculation of the jewish calendar http://www.jewfaq.org/calendr2.htm.

i translated the formulas to excel a few years ago and i thought i should translate it to GP as well. the resulting program takes a hebrew year and determines rosh hashanah (jewish new year) for that year.