Attempting to prove to me that Judaism is the only true religion, a friend of mine read to me from a book titled, The Coming Revolution, that the Zohar (a 2nd/3rd century CE commentary on the Torah allegedly written by Rabbi Simeon bar Yochai) uses a highly accurate value for the duration of the full moon cycle (29.530588853), centuries before this calculation could be made by modern calculators. How true is this claim?
My Google "skills" were unable to find who was the first person in history to come up with the calculation (NASA?). The only thing I could find, more or less related is this page using Gematria to calculate the moon cycle. But honestly, I'm not too sure what to make of it.
Note: Some people think the Zohar was written by Moses de León in the 13th century which, if true, would still be ages before NASA.