Arranger editor - duration and song time

Can someone tell me what “duration” and “song time” are in the arranger editor on the arranger track?

I’ve tried to work it out but they seem to relate neither to time nor bars and beats.

It’s there because if you want to repeat a section in the arranger editor. The duration field holds the duration for the specific part and Song Time the total duration of the song:

Thanks for your reply.

I’ve worked out the error. It’s basing it from the project start time in “project setup” rather than where I had set “timecode to zero” which was at bar 3