What's the point of a valuation date?

Recently I've been in a discussion regarding a valuation of a company as of some date a few years back (it was for tax purposes). And someone (a BV professional) said "but we can't just pretend we don't know what happened after that date!".  That's exactly what we MUST do! The point of the valuation date is to have a sort of a cut-off date, a point in time at which we would like to know what the estimated market value of the company would be considering information we had at the time. For example, let's assume we're valuing a company as of 31st March 2009. Generally, today (it's May 2009) one wouldn't pay much detail to what's happened next as one shouldn't - and here there's usually no dilemma. Now, consider we were engaged to do this same valuation in 2012. A lot has happened since. We know how the company performed. Should this influence our estimate of the market value as of 31st March 2009? NO! At that time we didn't have the information we have now. Of course, market value estimate as of TODAY is (or - may be) different. But when valuing a company on a specific date you have to go back to that point in time and ask yourself "what information do I have now, how much do I estimate the market value of the company to be". Should this be any different whether you do it today or 10 years from now? No. Will it be more difficult to be objective and ignore the information you have 10 years from now? Definitely. But that's just something you have to deal with.

It's sort of like saying: if I had the information I have now at the time of the valuation date, would I have made a different decision? Perhaps. But I didn't and I couldn't! For example, when making forecasts - could anyone as of the valuation date (which let's say was 31st December 2006) have predicted the occurence and extent of the financial crisis and recession and their influence on cash flow forecasts? Since we know about this crisis now, would we have made different cash flow forecasts back then? NO, because back then we didn't know about this crisis.

I know for some people it's difficult to come to terms with it, but the valuation date has its purpose and an appraiser should only take into account the information he/she had on that date!