Early spring, spring, late spring... what does that mean?

Gaaaahhh! I'm getting frustrated! This is my first year planting bulbs, and I'm trying to time it to where I have blooms each month. I'm over-thinking things, I know, but I'm terrified I'll wind up with a repeat of this year's garden-- long stretches with no blooms. Most all the suppliers have bulb helpers that list early spring, spring, early summer, etc., but I"m having a hard time translating that to actual months. I'm in zone 6, Oklahoma. Is there a resource I can find that will translate this into a useful calendar?

Maybe this will help you. The times on here are pretty close to what I find in my zone 6 garden.
http://www.gardentimeonline.com/FallPlantedBulbs.html

Try Scheepers' catalog too. They often list a month of bloom instead of a general "spring, summer."
http://www.johnscheepers.com/catview.cgi?_fn=Bulbs

Of course your weather for that winter and spring will have an effect on bloom too so the bloom times aren't cast in stone.

Some of the good gardening and bulb books have charts that show you generally what blooms when. That would probably be the easiest way for you to plan.

Thanks for that link, Hart! That's exactly what I was looking for.

Also depends on where you live. "April" in the Scheepers catalog means March here. Most of their bloom times are based on zone 5 standards in the northeast, where they're based.