Does anyone have any experience with booking hotels for day hours?  Any caveats or experiences worth relating.  (I don't have an RV!).  

Sometimes they accommodate early check-in. I've never done it but I gather it is common enough.

Not too many have explicit day rates, but if you are in a big metro area or near an airport with a lot of international flights, there are probably one or two dozen that have rates for something like 8:00 am check-in, 5:00 pm check-out.

Also, you can try to check in early. When the teams who worked for me and I would fly to Europe we might arrive as early as 7:00am. We would try to check in as soon as we arrived at the hotel, and sometime we could other time we couldn't and ended up dropping off luggage and going for a leisurely break fast before checking in until the texted us to say the room was ready or wait for the official check-in time, usually something like 3:00 pm. Not really a good basis for planning of course.

Most won’t let you rent by the hour. Your better off getting a decent place for 1 day and then just using it for the time you need. Run by the next morning and check-out. Some places you can just do mobile checkout and leave the access card in the room so you don’t need to stop back.

http://www.nypost.com/p/news/local/manhattan/le_parker_meridien_quickie_rate_1iSfLsp9bz1FvVsK2MsxPO?CMP=OTC-rss&FEEDNAME=
http://www.huffpost.com/entry/why-hourly-hotels-are-no_b_9212778

http://www.dayuse-hotels.com/
http://www.dayguest.com/
http://www.hotelsbyday.com/en
http://www.dayrooms.com/en/
http://us.roomforday.com/
http://www.daybreakhotels.com/
http://hourlyhotelsnearme.com/
http://www.byhours.com/en.html

dayuse.com   Highly recommended
.
Always  take a copy of your online booking confirmation with you.  Doesn't happen often but I've encountered the occasional hotel who does not have any tracking of the reservation.  Never really an issue but clunky.  Overall, a good solution.