There's no limit as to how many times you can do that. However there can only be one Pokemon to be taken back on the friend board at a time (minus events). If you exit the DW without waking up and use it the next day, you'll be left with whatever you had just before you left the previous session.
Originally Posted by varanus_komodoensis
Successful Serebiiforum Wi-Fi trades (51): Redblood012, jabs4, NoobPokemon, EH TuCker, talface, Palagerini, tyvaughn, Ubermac, BattleElf, kinder suprise, "Freak" owns, ninjakitten, cyclo195, Poke Rock, LegndKillr83, Merchant, Petal (x4), Penguin_Man, caffeine87, MegaGalvatron, Jirachidude, Dragon Rules, Wicked Weavile, Stevenwoo (x2), dax324, VealChop, Troggy, J.T., zivc, DaRkJoLtEoN, pkfan, faethemoose, thegreattjtoot, Zormon, ebevan91, Pharosher, The Apostle, Bloodflowers, Cear13, Celestial Moth, hawkmbl, Mare, ShinyRay5, Italianbaptist, MechanisticMoth, Earendil, Pokemon Professor