[Updated October 1, 2008]
Consider the following provision:
During the term of this agreement and the following 24 consecutive months, the Consultant shall not …
In this context, the word consecutive is redundant. The same applies to use of consecutive with other units of time.
But consider this provision:
The Employee shall spend two months every year in Acme’s Budapest office.
The employee could elect to spend one week a month in the Budapest office each of the first eight months of 2008 and presumably be in compliance with that obligation.
So if you’re referring to a period of time before or after a point in time, consecutive is redundant. But if you’re referring to a period of time within a larger period of time and you want the shorter period of time to be treated as one block, you should use consecutive.

