Last week we began asking for rain with Mashiv HaRuach U’Morid haGashem. On Oct. 13 (7 Cheshvan) we in Israel will insert an additional petition for rain,V'tayn tal u'matar, in the Amida’s bracha "Barech Aleynu," as we ask for G-d's sustenance, which is linked to rain, now needed in Israel. Shmuel the Sage fixed the Diaspora petition to begin on the 60th day after the autumnal equinox (when rain was needed in Babylonia), a solar figure falling out on either Dec. 4 or 5. This remains the Diaspora date. One who forgets this petition must repeat the Amida. If in doubt, he must repeat the Amida unless he’s said the phrase for 30 days (or repeated it 90 times!) to habituate himself to saying it. An Israeli travelling abroad between 7 Cheshvan-Dec. 4 should pray like the community he’s in, but should add Tal Umatar in the Amida’s Shomea T’fila. He may act as Chazan & add his "home" version of the prayer in the silent Amida, but should join with the majority when reciting the public prayer.