Silver jubilee is a celebration held to mark a 25th anniversary. The anniversary celebrations can be of a wedding anniversary, the 25th year of a monarch's reign or anything that has completed a 25-year mark.
Sultan Mizan Zainal Abidin of Terengganu, Malaysia is expected to have his silver jubilee in 2023.
Silver jubilee Wikipedia
In Pakistan and India, a silver jubilee film is one shown continuously in cinemas in one city for 25 weeks.