Admittedly, the scheduling in Ioniqs is less than helpful...

If you are using L2, chances are 12a to 6a is enough time to complete charging. so just go with that.

 

My home EVSE can have a different schedule for weekends. And TOU hours are different between home and our cabin. So I just have the EVSE do the scheduling.

 

Currently, I have to go into the settings every Friday and change the end time to 2p, then go back in on Sunday to change it back to 6a

You can start charging outside the schedule by pressing the 'hold' button inside the charging door.

It's not a great solution but, you might be able to just leave the schedule at 12 - 6 and manually start charging when needed between 6 am and 2 pm on the weekends. Although, you might also need to remember to manually stop charging at 2 pm. So, my 'solution' might end up being just as annoying as changing your schedule every Friday and Sunday.

Update

I tried to reproduce the scenario I suggested above. My charging schedule ends at 4:00 pm so I plugged in around 3:50 pm and let the car charge. Then, around 6:15 pm I went back to the car to try starting an 'override' charging session.

A problem I ran into was that the SoC indicator and the two buttons inside the charging door were not illuminated. Pressing the 'Hold' button had no effect whatsoever.

I tried unlocking and then locking the car - that also had no effect.

Then I disconnected and reconnected the charging cable. At that point the SoC indicator and the two buttons lit up. Then I pressed the 'Hold' button and the car started charging. So, the scenario does work, but it is even more fiddly than I thought.

 

As Arob and Frank suggested, I would expect midnight-6am to be plenty of time for nightly charging on L2. I have my schedule set to charge from 2am-6am with a 40amp home charging setup which gives me about 10% per hour so it only rarely needs more than those 4 hours.

 

I have the Emporia charger, and that lets you schedule based on day of the week. I like having the charger determine time, that way if I'm out and about I don't have to make changes on the car end. Also, look into seeing if your service provider offers hourly charging. By me, between around 1am and 6am is always the cheapest, sometimes dipping into negative territory (where they actually pay you to charge ). They'll also send text updates when the price is peaking.