[LAD] Time & How to approach it

Hey all, I've been dev-ing MIDI/audio programs in C++ & Python for a while, but I'm struggling with one concept: How to approach time. If i want to "schedule" events for the future, what is the "correct" way to do this? I've read some docs about Jack's timebase & transport system, ideally I want to support that, but I dont seem to grasp the "whole". I could write a class that has a "MIDI clip" inside it, and then play back multiple of these clips from thier classes. Or should I approach more along the lines of each MIDI clip being inside a std::vector<MidiClip>? How does eg: Seq24, Ardour, RoseGarden etc approach the time management? I've attempted to read docs/sources, but the projects are too big for me to understand how the "time-system" works. Hope somebody could shed some light on this, -Harry PS: If there's a tutorial or simple example I could read, please say, I've googled but not found any tutorial on the subject.