I used to Event one of mine around working full time and he was also on DIY. As others have said, having a time restriction of when you can and cannot be at the yard isn’t going to help you so may be best to look for somewhere with mor flexibility long term.
I used to finish work at 5 and then be at the yard for around 5.20. I would never ride the day before unless I wasn’t working. I would bath the night before and get as much of my stuff together and in the lorry as possible. Haynet and water for the next day would also be prepared. I always make feeds for the morning the night before to save time. I would chalk his legs to save time the next day too. (yes I even used to chalk for Eventing!!) He was hogged so I didn’t need to plait. I would be at the yard however long this took me and then I’d take my tack home and clean it at home. Sometimes I would do it the night before if I knew I wasn’t going to be riding again before the Show.
On the morning, it would be arrive, feed, skip out if time, quick groom, brush off the chalk and oil his hooves and load up and go.
It is doable, you just need to very organised. Good luck!