There are a few values used for time in SCORM, the two big ones are going to be Total Time and Session Time.
Session time is going to be the amount of time a learner spent in the course during the current session. This is going to be set by the course itself. Note, this is not mandatory.
Total time is going to be the sum of all the session times set by the course. This is accumulated by the LMS.
For example, if you are testing in SCORM Cloud, you will noticed two different total times, Total Time and Total Time Tracked.
Total Time Tracked is the total time that we, on the player side of things, track just in case the course doesn't set time.
Every so often, there is a small difference in those two values due to the fact that the course has an idea of how it tracks time and we are just going to track the time that the course was opened until it was closed. On top of that, there is a latency variable for interactions, this will track the moment an interaction becomes available to a learner to the time it was first answered.
If you have any questions, please send a message to firstname.lastname@example.org.