The levain has always been ready a few hours after the 3rd feeding. There are several ways to make it work around your schedule. The 4 hour feeding schedule does not need to be strictly followed. You can let it go 5-6 hours or more if necessary. When I building the levain, I will usually start it in the morning. If it's a Saturday, then I can feed it during the day. If a weekday and my wife or son are home, I can have them do the feeding. If nobody is home, I will start it in the morning and take it to work along with pre-measured water/flour mix for the second feeding, then do the 3rd when I get home.
Once fully active, I put the levain in the fridge and keep it till the next morning, or up to 24 hours before I make the dough. So you could make the dough the next evening. Once the dough is made, you can either let it rise and then bake, or retard it in the fridge for several days.
So you have a lot of flexibility with it and should be able to work it around most schedules.