By 'relative tenses', I mean a form of tense that is independent of the main tense that indicates when an event occurred relative to the past or future.
Examples in English would be:
I spoke. I will speak.
I had spoken. I will have spoken.
I was going to speak. I will be going to speak.
Of course, obviously the 'past-in-the-past' tense would be called a pluperfect, but isn't there any names for a 'relative tenses' on its own? They obviously exist, but the only place I've heard about them is in Tagalog (though those were originally misinterpreted as simple tenses rather than relative tenses, for example their 'past' can mean either 'this happened' or 'this will have happened').