No, it's not really useful to rely on the official declarations of recessions when investing.
However, Google Trends offers better services. Entering the keyword 'recession' in January 2008 provided a warning that was much more timely than the NBER cycle dating committee. Better yet, the keyword 'subprime' formed a peak as early as in March 2007. Early enough to do something with the information:
By the way, the stock market noticed on in October 2007 that something was going wrong. So much for the Efficient Market Hypothesis.