>It just occurred to me that I might be able to use my code that calculates the date of Easter, to also calculate the dates of both Rosh Hashanah and Yom Kippur provided there was some sort of relationship between the Paschal moon and the beginning of the Jewish New Year. Is there one?

Hmm, I'm not sure. As I understand it, Easter comes on the first Sunday after the first full moon after the Spring equinox. Passover comes on the 15th of Nisan, which is always a full moon, but I'm not sure it always comes after the equinox.

To make matters more complicated, Rosh Hashanah can only come on certain days of the week (to prevent the second day of certain holidays from falling on the Sabbath). So, I believe the calendar gets fiddled (by having some months have a one day Rosh Hodesh - beginning of the month - while others have two days). We've also reached the bounds of my knowledge, I think.

Our high holiday prayer book likes the dates of Rosh Hashanah for a 20-year period or so. We have older and newer prayer books around, so I can probably produce a list from sometime in the 70's until sometime in the 20's. If you want, I can send you a list and you can see whether there's a correlation.

Tamar