Google can predict the future...
Tonight I was playing around the Google and trying to figure out how its queries work for my GoogleTool and it appears that Google can either see into the future or someone there needs to double check their math.
For those that have looked into the Google API you will notice that you can include a date range in your query specified, daterange:<startDate>-<endDate>. If you read the reference you will see that Google does its indexing using Julian dates, the interval of time in days (and fraction of a day) since Greenwich noon on Jan. 1, 4713 BC, thus your start and end date must be specified in this manner.
While I am not a historian, nor a math major, nor an astrologist I do believe that through my research I have successfully mastered the computation of a Julian date and I am confident my code is correct. I did want to be sure that my code was correct, so I searched the web using the MSN Search (since I can't trust Google right now) and found various Julian date calculators. I tested various dates and the computations from theses calculators as well as my own computations appeared to always match up, thus I have reaffirmed that my computations are correct.
So now to the delimma...
Today's date based on the Gregorian calendar is: December 14, 2004
Today's date based on the Julian calendar and my computations is: 2453353 (this was floored)
Here are some test queries run against Google and their estimate results:
- Microsoft daterange:2453353-2453353
- Results: 396,000
- Let's assume that Google's computers are running on GMT so that means they have had about 7 hours to index content for today. I am not going to underestimate Google's power, but that seems a little excessive even for something as powerful as google.
- Microsoft daterange:2453354-2453354
- Results: 496
- As we can see Google's result set dropped at an alarming rate, but shouldn't this have returned 0? I just searched for all of the pages that were indexed on December 15, 2004 as far as I know it has no where in the world has reached Dec. 15th yet.
- Microsoft daterange:2453366-2453366
- Result: 1
- It appears that Google has indexed one page on December 26, 2004 based on the Julian date index.
As you can see based on these few queries Google's date calculations appear to be off somewhere of the mathematics from the U.S. Navel Observatory are incorrect. What do you think? Is Google really incorrect? or is the rest of the world wrong?
I would really be interested to know the real answer since it will have a dramatic impact upon the accuracy of my GoogleTool.