As charley says, a lot of it is to do with how many other women are delivering. Midwife staffing should be the same, but there'll be fewer doctors around. Notably anaesthetists.
September isn't always too bad. Anecdotally, my Wednesday start, early September induction got me onto delivery suite at 3am Thursday morning, even though I wasn't quite ready to have my waters burst yet. They only had one labourer at the time (the only other Wednesday induction), and were desperate.
However, my Monday start, early-mid March induction saw me finally reach delivery suite 8am Friday morning. Women kept coming in in spontaneous labour, bumping all the inductions back. Then there were emergency inductions, which by there nature were triaged to the top of the list. And then some women waiting for inductions also went into spontaneous labour/waters broke, hopping the queue. I think I was told I was third on the list to start. I dropped to eighth at one point.
Tbh I would take the Thursday slot. Still a weekday, and hopefully you'll be down on labour ward on the Friday. If you're going to get an epidural, request it before before 4-5pm, and definitely before 8pm. Bitter experience talking.