This came from the Saint Paul Area Council of Churches and is totally helpful.
Jewish High Holy Days
Acknowledging our Neighbors of Different Religious Traditions. We (name of congregation) extend our prayers and regards to our Jewish neighbors (optional: particularly name of neighboring synagogue) on the occasion of their most sacred time of the year, the High Holy Days, which begin with Rosh Hashanah, the Jewish New Year (sundown Sept. 24-26) and climax with Yom Kippur or Day of Atonement (Oct. 4).
Jews will pray and celebrate the gift of the new year on Rosh Hashanah and fast and pray for repentance on Yom Kippur. “Shana tovah” or “Happy New Year” is an appropriate greeting for these holy days for Jews.
Sample Prayer: God of all people, we honor our neighbors who follow the religious tradition of Judaism and we ask your blessing on our Jewish neighbors and Jews around the world as they observe their High Holy Days of Rosh Hashanah and Yom Kippur. May the gifts of their tradition be a blessing to them and they to all people as we all seek to find peace, justice and sustainability in our challenged world. Amen.