Workers Comp Annual Limit?

We have a workers comp "rating period" from 08/01 of one year through 07/31 of the next year. Is this so unusual? (Seriously, I don't know - is that unusual?) Apparently, you can set up annual limits for workers comp (for officers of the company) and only calculate up to a certain $$ limit. However, that limit can't cross calendar years like our policy does.

--Is it unusual for a policy period to cross calendar years like ours?

--Have you ever run into this? How have you worked around it?