I did Tokyo in 8 hrs just for Sushi. Land in NRT around 4pm and take off from HND around midnight.
Not quite a day trip as the entire trip was something like 36 hours, starting in SLC.

Have flown to SJC and drove to Santa Cruz just for a bike ride and returned that night. Santa Cruz bicycle company has demo bikes for $20 and a decent trail system, Wilder Ranch, just down the road so you do not need a rental vehicle that can carry bikes.

I will probably do a day trip to SFO this winter to demo a bike in Fairfax.