There are no months in my calendar, just 365 days in a year (or 366 if it's a leap year). With my system, I can compute the distance between my birth and any event in history, famous or otherwise: the Declaration of Independence was signed on 366/205 B.L. (Before Leighton); Columbus first set sail on 30/488 B.L.; and my brother was born on 361/10 L.E.
Notice that the number before the slash represents the day, and following the slash are the year and era (B.L. is "Before Leighton;" L.E. means either "Leighton's Era" or "The Leighton Era").
Those who know my birthday will observe that although this is the 23rd year L.E., I am only 22. This is because my system, like the Gregorian Calendar used by the Western world, does not have a year 0. Just as 1 C.E. follows 1 B.C.E., 1 L.E. follows 1 B.L. I turned 1 year old on the first day of 2 L.E.
Why on earth would I want to do this kind of thing? I just wanted to have a little fun, and learn some things in the process. It's interesting to find out first-hand, even with such a simple exercise, what is involved in switching between two different calendrical notations; having spent the better part of two afternoons doing so and setting up this page, I have a greater appreciation for those who effected the switch from the Julian to the Gregorian calendar. I didn't even tackle one of the more difficult parts, namely coming up with an entirely new way of measuring the length of the year. I just imported the Gregorian usage of leap years. (Not all calendars consider years to be the same length: see some of the links below.)
It's possible that some people might not appreciate this kind of thing; after all, two of the most commonly used calendrical systems--the Gregorian and Islamic calendars--were originally based on key events in the history of the Christian and Muslim religions, respectively. I'm certainly not trying to place myself on the level of Muhammed or Jesus. In point of fact, such an organization of history into only two eras, with the division between them being a single event, is only one of several ways to divide history.
The Chinese calendar is a sequence of sixty-year cycles, and there is no key event dividing one era from another. The Mayan calendar, on the other hand, has the projected beginning and end of the universe as its starting and stopping points--3114 B.C.E. and 2012 C.E., respectively (6094 B.L. and 33 L.E.). More common than these, however, was the ancient practice of measuring eras in terms of who was on the throne.
What I've tried to do here is give an idea of how arbitrary the way we think of history and past events can be; any dates we memorize are dependent on our particular calendar. Surely a more appropriate approach to history is to try to get a sense of when things happened in relation to other things. Not only is this relatively independent of one's choice of calendar, it gives a better idea of how events interact with each other.