Full Idea
If region A locally freezes (for one year, observed by the other two regions) every third year, and region B every fourth year, and region B every fifth year, ...then every sixtieth year there will be a total freeze lasting one year.
Gist of Idea
If three regions freeze every 3rd, 4th and 5th year, they all freeze together every 60 years
Source
Sydney Shoemaker (Time Without Change [1969], p.56)
Book Reference
Shoemaker,Sydney: 'Identity, Cause and Mind' [OUP 2003], p.56
A Reaction
One of the most brilliant thought experiments in modern philosophy!!! He demonstrates that there can be time without change, but also that we must rely on best explanation, and that there is more to ontology than epistemology (let alone semantics).
Related Idea
Idea 16697 Time is independent of motion, because God could stop everything for a short or long time [Crathorn, by Pasnau]