- Mitzvot in Time and Space - 25 Nisan 5761; April 18, '01
- The Rambam's impact on Kiddush Hachodesh and Jewish astronomy - 27 Nisan 5764; April 18, '04
- Eigth Convention: Kiddush Hachodesh, Halachic Times, and Jewish Astronomy - 24 Nisan 5765; May 3, '05
- Parah Adumah Seminar - 23 Adar 5766; March 23, '06
- Ninth Convention: Kiddush Hachodesh, Halachic Times, and Jewish Astronomy - 26 Nisan 5766; April 24, '06