What is the length of time represented by the sequencer timeline?

Seems a simple enough question. I have to synchronize things to an audio sound track. I know I have to have something begin happening at 3 seconds from the beginning of the track but all I’m seeing is a set of numbers with no default meaning attached. Nowhere in any of the documentation can I find a way to caclulate for a specific time interval. All the examples simple have you set cues at a numeric point without telling you why that point is selected. Is at 1.0 x speed a time point reflecting seconds? Microseconds? Milliseconds? Picoseconds? Why is something so fundamental to a timing exercise omit such a basic reference in the documentation. And yes, I Googled multiple variations around the terms “Unreal” and “Sequencer” with the hope that something turn up. It seems it’s one of those things they expect a developer to “Just Know”.

Bump. I too would like to know. Edit: " Since its inception, Sequencer has represented time as a number of seconds , using a floating point number "