Honestly, I personally didn't have much difficulty just spamming CTRL while replaying... the only problem was the daily weekday class animated chibi that can't be skipped. The animation is like 5~ seconds long? But it shows up a lot of times throughout the game so it ends up taking up a LOT of time. Let's say it shows up on 200~ days... if you add up the time 200 times, you actually spend at least 15 minutes watching this animation per route lol. It's really unnerving.
This skip days function is nice to unlock specific CGs but I would really appreciate if you could make it so the weekday voice acting class chibi could be skipped (I mean all the other chibis can be interrupted by pressing CTRL, but for some reason that one chibi is impossible to skip). This way it's not necessary to use the skip days function and we can just normally skip our way through the game without missing out on days :)