With the Wesker/Jill fight, just time yourself manually and if you feel the fight is taking too long, just hit reset and try it again. That way, you don't have to keep doing the whole chapter, just the one part. Like another person mentioned earlier, the clock resets when you reset the checkpoint. This way, you can also try different weapons and such to see what works best for you against Wesker.
Your Mainbar:






