Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Hertz Global Holdings (HTZG.Q) are being thrown in reverse, down as much as 4.7% today following news that it will miss the deadline for filing its 10-K and will need to file a 15-day extension.

So what: Hertz blamed the delay on the implementation of an "enterprise resource planning (ERP) system to improve its financial disclosure controls." This resulted in "significant issues during the preparation of its annual financial statements which affected its resources and overall system of financial reporting." In other words, it wasn't up to speed in time for the report.

While that may be easily forgivable, the part that is getting investors a bit spooked is that Hertz warned that the new system identified "certain adjustments relating to prior periods which will require the Company to revise certain of its previously issued financial statements." Restatements are rarely fun.

Now what: Although Hertz said it doesn't "expect" the adjustments to be of a material nature, the market hates uncertainty especially on a widespread red day. There will naturally be a bit of concern that the adjustments may turn out to be more severe than Hertz originally thought.

Hertz didn't give a specific date for its earnings release and conference call other than that they will occur in "conjunction with filing its Form 10-K on or before March 18, 2014." The lack of a committed time this late in the season is a bit unsettling.

Analysts expect Hertz to report $10.84 billion in sales with earnings per share of $1.70 for the year. Look for the 10-K to be filed by the 18th. If it is, and with no material adjustments to prior years as is expected, and earnings and guidance come within expectations, then the weakness may prove to be opportunity. However, cautious Fools may want to wait on the sidelines until this (hopefully) temporary fog of uncertainty clears.