There's no time limit, as far as I know, as long as the bulbs themselves are still firm and healthy-looking. I wouldn't delay too long, however, because they'll often take it into their heads to start growing on their own and you can end up with stunted or so-so blooms as a result. If you have to hold off planting them, I'd suggest holding them somewhere dark, dry and cool (not cold) until you're ready. Those conditions will help keep them dormant/resting as long as possible.....Someone else might have other thoughts.........Good luck!

Thanks for your helpful posting, kathicville! I went ahead and planted them in some pebbles, and so far, so good. I also read somewhere that if you add 5% alcohol (vodka, gin, etc.), they will be less leggy. Keeping my fingers crossed. Nothing like the scent of paperwhites. Thanks again!