The other day as I was poking around the Internet I kept coming across the following date: December 29, 1967. If you are not a Star Trek person, you might not know that that’s the date that the Trouble With Tribbles episode was first aired (at least according to the many sources I kept coming across — I have not cross-checked and alas, I am not a Star Trek person.)

This amused me and I wondered exactly how much time had passed since that episode aired. Google can do some mathematical calculations so I figured I might as well try it for dates. So I went to Google and tried:

December 29, 1967 – December 29, 2009

That got me results — over 12 million of them as a matter of fact — but nothing about date calculation. But you know, as soon as I saw the results I thought to myself, “I bet Wolfram|Alpha could calculate these dates for me.”

And I was right!

I went to http://www.wolframalpha.com/ and entered December 29, 1967 – December 29, 2009 and WA gave me the following output:

As you can see, WA calculated that I was looking for the space between two dates and gave me the calculations in years, weeks, and days. It also helpfully informed me that December 29, 1967 was on a Friday.

After I played with this for a while (finding out *exactly* how many days you’ve been alive may make you a little tired) I wondered if WA could do calculations based on dates. For example, would the following query work?

Fifteen days after December 29, 1967

Yes, that does work. It gives you the date (Saturday, January 13, 1968) calculates the time difference between that day and this one, and then proceeds to give the information it normally does about a single date (notable events, date formats, moon phase, sunrise and sunset.) It works if you’re looking for dates counting backwards from a specified date as well.

I decided to through a curve ball at WA. Since it lists the moon phrases, I figured it should be able to calculate dates based on the full moon. So I asked it:

Fifth full moon after December 29, 1967

And it gave me an answer! According to WA the fifth full moon after December 29, 1967 was 9:06:35 am EDT Sunday, May 12, 1968.

I tried asking WA about the first solstice after December 29, 1967. It got that one right. I finally tripped it up asking for the first sunrise that was exactly 7:05 AM after December 29, 1967. And even now I’m wondering if my syntax was screwed up.

Wolfram|Alpha is a great compliment to Google; they’re not competitors. Being able to play with dates is just one more proof of that.