What is the statute of limitations for a class action in the USA?

What is the statute of limitations for a class action in the USA?
3 years is the "general" statute of limitation on most class actions such as intentional tort, quasi-contract, and the likes.

However, there are exceptions to that and they vary widely and extend as long as 10 years as in the following example:

"....suing under the Alien Tort Claims Act (ATCA), which has a statute of limitations of ten years and concerns torts relating to personal injury, not property."