Question Flights to Santorini - What's the Latest Arrival?

We just booked our Greece trip for April and will be landing in Athens at 18:50 on a Sunday. I’m trying to figure out how late we can catch a flight to Santorini the same evening. Are there any late flights available that you know of? Also, any tips on the best way to transfer from Athens to Santorini in the evening would be super helpful. Thanks in advance!