Yes, but you can't check your bags in 24 hours before a flight. Also, I think you can only do on-line check in that early. Can you actually check in 24 hours before the flight at the airport (unless you're on a connection?)

In any case, my guess is that will-san wants to dump off some bags at the in-town check in and then go out for a bit.

Will-san, the other problem with this is that you need to use your Airport Express ticket to get into the check-in area, so the intention is that you go right to the airport.