He grew up in a secular Jewish family in Elkins Park, Pennsylvania, the son of David Kubert, an attorney, and Adele (Sion) Kubert, a high school teacher.
Daniel graduated from Philadelphia's Central High School in 1965.
Kubert served as a Gibbs Instructor at Yale University from 1973 to 1975.
[1] His work on modular units was done in collaboration with Yale mathematician Serge Lang.
Kubert was hired as an assistant professor at Cornell University in 1975,[1] and was still there at the end of the decade.