1,199. Is There a Statute of Limitations on Testifying?

181:19 If Jew has testimony favoring an idolator who has a court case with a different Jew in a non-Jewish court, if his testimony would cause the Jew to be liable for more than he would under Jewish law, he may not testify; otherwise, he may. If the idolator initially arranged that the Jew would testify for him, since reneging would be a desecration of G-d's name, he may testify for him in any case.

181:20 So long as a person remembers, he can testify. One need not worry that because an incident happened a long time ago, he won't remember it properly. Even if he only remembers his testimony by referring to his notes, when they give him what he wrote at the time and has now forgotten as a reminder, he may still testify so long as seeing what he wrote makes him remember. Similarly, if he's reminded of the matter by another person, he can still testify. This is true even if the one who reminds him is the second witness. However, if one of the litigants reminds him and he remembers, he may not testify.  However, one litigant may state the facts to another person; if he reminds the witness, it counts as being reminded by a third party.