We describe when debt collectors can and cannot call you in the first chapter of our ebook Debt Collection Answers: How to Use Debt Collection Laws to Protect Your Rights. The first chapter is posted online where you can read it for free. I am going to strongly encourage you to do that because I want to make sure you understand your basic rights in dealing with debt collectors.
To answer your question directly, though, generally they can't contact you before 8 am or after 9 pm local time. There is no prohibition against weekends, unless you explain to a debt collector why they can't contact you then. You'll find more information about that when you read the first chapter.
