I’d like to show you a very common Mac OS X dating mistake – and how super easy it is to fix. What’s that? You don’t use your Mac for dating? Pshaw, people. If you’re letting CheckBook, our sweet personal finance manager, help manage your monies then you’re definitely – oh, wait, I meant date formatting mistake. You thought I was about to give out free dating advice, didn’t ya?
So, you’ve decided to tweak the way your Mac displays dates and found your way to the Language & Text preference pane in System Preferences. Â You’ve even gone into the Formats tab, looked around and hit the Customize… button. Â So far, so good. Here’s something similar to what you’ll see:

Default Language & Text Date Formats – Pay Close Attention to The Blue Around the Numbers
Now let’s say you want to change the Short format so that you get 4-digit years. Â What do you do? You get rid of that “11” with the nice blue background and type in a 2011, right? Like this:

A literal year in the Short Date Format
And you’re good to go! Until…well, until you notice all the dates in all your apps are showing up with “2011” as their year, no matter what you do or how many times you try to change the dates. Â It’s a little bit like you’re John Malkovich being John Malkovich. Â Only not as creepy. And not as messy in the end (promise!).
But what just happened?
In the first screenshot everything besides slashes and commas had a blue background. In the second screenshot, after we typed in our 4-digit year, that little bit we typed didn’t have a blue background. Â You’ve probably guessed by now: Â that blue background is the key. What’s so special about it, anyway? Â Well, everything with a blue background is actually a placeholder for a part of the date, like the day or the year. Â Behind the scenes, when the Mac has to show you a date it looks for these placeholders and swaps in the appropriate values – but the parts of the date format that don’t have a blue background are just copied to the final date you see on your screen. When we typed in “2011” in place of the old “11”, we replaced the placeholder for the year with a literal bit of text – and now every date gets a “2011” where the actual year should be. Drat!
How do we fix it?  That’s the easy part!  First, remove the “2011” you typed in earlier. Second, look at the lower half of the window, where you’ll see all sorts of “date elements” – and they all have blue backgrounds!  Find the Year date element, which in this case is a “2011”, and drag it up to the end of your Short format, just to the right of the final slash. It should now look like this:

The Short Date Format with a proper 4-digit year
And that’s all there is to it. Â You made your mistake but an easy drag and drop made everything better. Â Now if you want to take this dating thing to the next level…take some initiative and see what happens when you click on the date elements that have little white triangles in them…