You can plant it any time. I usually just plunk my forced, potted bulbs in the ground as soon as danger of severe freezes is over.

No one goes around and digs them out of the ground after they bloom naturally, now do they? ;-) They spend the summer in the ground on their own, and will be just fine.

They are sold and planted in the fall because they ripen in the growers' fields between May and July, depending upon species of bulb, and then it requires a few more weeks to dig/process/package/ship. Fall planting is more for logistical than horticultural reasons, they could actually start selling the first bulbs to ripen, such as crocus, in June if they really wanted to.

I'm not sure what the effect of refrigeration may be -- its possible it will make the bulb think its gone through a winter, and it may grow again when you plant it -- kind of depends on how long it's been in there. This won't hurt anything, there is plenty of time for it to go through another entire cycle prior to fall/winter cold.

I'm not sure what the effect of refrigeration may be

Depends on what's in the frig with the bulb :-) Lots of fruits and veggies produce ethylene gas as they ripen. This will prevent the development of flowers in any bulbs and can promote rot. You always want to keep flowering bulbs stored separately for cooling.

Otherwise I agree with all of the above - plant as soon as you want, with sooner being better than later :-)

Thank-you very much. This puts my mind at ease and helps make sense of some of the things I've read. :)