What is a jubilee? I'm glad you asked, because I did not know. My dictionary says:
jubilee
n.
ME < OFr jubile < LL(Ec) jubilaeus < Gr(Ec) ibbclaios < Heb ybbcl, a ram, ram‘s horn used as a trumpet to announce the sabbatical year: infl. by L jubilum: see JUBILATE 6
1 Jewish History a year-long celebration held every fifty years in which all bondmen were freed, mortgaged lands were restored to the original owners, and land was left fallow: Lev. 25:8-17
2 a) an anniversary, esp. a 50th or 25th anniversary b) a celebration of this
3 a time or occasion of rejoicing
4 jubilation; rejoicing
5 R.C.Ch. a year proclaimed as a solemn time for gaining a plenary indulgence and for receiving absolution, on certain conditions: an ordinary jubilee occurs every twenty-five years