It depends on the percentage of dihydroxyacetone and erythrulose in the self tanning lotion. (I assume you're referring to fake tanning as UV tanning is a long-term commitment.) But even on self tanners with a low DHA and Eryth percentage, there's still no way to wash it all off in one day. It takes 3-7 days to wash off completely.
However, there are self tanners that are purely cosmetic--meaning, they WILL wash off in your first shower. Here's one for example:
http://www.lotions2go.com/2013-New-T...-Dark-68z.html There are others you can buy at Walgreens, etc. like Loreal or whatever.
You rub these on your skin and they instantly bronze you (whereas the DHA/Eryth self tanners will take 4-8 hours to develop). They're very easy to apply and are more of a stain on your skin, so you wouldn't have to worry about it rubbing off as much as body paint.