tin anniversary

plural tin anniversaries

1. informalThe tenth anniversary of something, especially a wedding.

   And a couple marrying at age 65 today can look forward to their tin anniversary, or at least 10 years of marriage.

   1977 September 9, “The Golden Landmark”, in The Sumter Daily Item

   2 more examples

   Their tin anniversary [Prince Charles and Princess Diana's] today has been kicked around by Fleet Street so hard it almost rattles, but millions of Britons and other royal-watchers around the world are wont to hear all the dirt, making publishers of racy newspapers and glossy magazines rich.

   1991 July 30, Craig R. Whitney, “An Anniversary Dinner That's a Feast for Gossips”, in The New York Times

   The connection to a possible launch is that Apple opened its first two retail stores on that date in 2001; suggesting the Cupertino, Calif.-based company might be planning something special to celebrate its tin anniversary.

   2011 May 17, Jameson Berkow, “Bootup: Major Apple product launch rumoured for Thursday”, in Financial Post

   Synonyms: decaversary, decennial