It has more to do with the water temperatures than the time of year, however, the length of the daylight does play a factor as well. But to demonstrate this point, bass in Florida are spawning right now while the fish in Minnesota may not spawn until late June or early July. In New Jersey, some bass can typically be found on the beds between mid April and early June with the middle part of this period being the peak of the spawning period. Not all of the bass will spawn at the same time either. Some will spawn early in the season, some later.
Smallmouth TYPICALLY start moving onto bedding sites when the water temps average 50-55 degrees. Largemouth TYPICALLY begin moving to bedding locations between 55-60 degrees. Actual preferred spawning temperatures for smallmouth are around 60 degrees while prime spawning temperatures for largemouth are around 65 degrees.
Of course these temperatures are merely guides and the fish obviously don't read the same books as we do so theoretical and actual spawning can vary depending on local conditions, type of cover available, availability of shallow water (warms faster), recent weather patterns, etc. You really need to get out and experiment on your local waters and observe fish behavior to know for sure. Don't just go out and fish, try to figure out what they are doing and why. After a few trips you'll be able to tell if they are pre-spawn, spawn or post-spawn.