Wait a second! How do I know that the events that I mention here actually happened on the given date? Without a doubt many of the dates that we know are "correct", meaning that someone can verify a particular claim that something specific happened on a particular date by checking somewhere in an archive, or in a dated newspaper. But for numerous other dates it's probably hard to be totally accurate. Did a battle really take place on a particular date 250 years ago? And does it really matter?

Since this column deals mostly with communications technologies, I'm always on the lookout for a date on which a particular technology was first used:

On this day, Johnny Smith, from Somewhere Else, North Dakota, first used an eraser that was attached to his pencil in order to erase a mistake on his fifth grade arithmetic test, thus ushering in the era of pencils with erasers in education.

The first "book drop" was initiated by Pythagoras' geometry class today, when the pupils decided to play a practical joke on their beloved teacher. However, when four of the stone books caused broken toes, it was decided to postpone the use of the new invention until the widespread availability of books made of paper.