Rabbeinu Tam

Welcome to the Rabbeinu Tam (ר"ת \ רבינו תם) app! This app is a passion project that I made while in college. While I was in Israel, I always kept Rabbeinu Tam every שבת (Shabbat/Shabbos) according to the Ohr HaChaim calendar that went according to Rabbi Ovadiah Yosef ZT"L. However, once I left Israel, I was no longer able to rely on the calendar.

I was told by my Rabbis that in order to get the time for Rabbeinu tam, I would need to take the amount of time between sunrise and sunset, divide it by 10 and add that number onto sunset, and that is what I did every week. I always calculated Sof Zman Rabbeinu Tam in my head every week and it was becoming a hassle. Therefore, I set out to create this app that will do the calculations for me.

I have also added multiple opinions into this app as well. I have included all the possible zmanim of Rabbeinu Tam that were in the KosherJava API. Whether it be temporal (zmaniyot \ זמנית) minutes, regular minutes, or degrees. This app has it all! (If an opinion is missing, feel free to email me and I will add it to the app as soon as possible.)

The biggest advantage of this app is the use of elevation (which the Ohr HaChaim calendar used). With this app, you can decide whether or not to use elevation to get true halachic sunset. You could, of course, add elevation manually (in meters), however, I have included a functionality that retrieves the elevation data from a website called ChaiTables (or LuchosChai in hebrew).

I do hope that this app will help people keep Rabbeinu Tam every week properly according to the halacha. If you have any problem please feel free to contact me at elyahujacobi@gmail.com.