If not, is there a way to estimate it (i.e. do any logs show how many chunks it will render, and then averaging the time it's taking to render x amount of chunks...understanding that it is only an estimate, and some chunks take longer than other chunks...)

[reason I ask, is I just started a render...and it seems like it is going to take long.  I need to know if it is like 16 hours long, or 3 hours long timeframe?]