DECATUR - The trouble with time is there is just never enough of it.

So make the most of today, when the calendar does its roughly four-yearly leap year hiccup and spits out an extra leap day, which we call Feb. 29.

Why do we call it leap year and leap day? The jury is still out on that one, although one theory is that religious festival dates after the intercalary day (official name for the leap day) leap one day forward. But that seems a little bogus, and nobody knows for sure.

Science can be a lot more precise about why we need leap year itself, and there is no better scientific source than John Lowe, who works out of a laboratory in Boulder, Colo. Armed with a doctorate in electrical engineering, he's employed by the National Institute of Standards and Technology, the keepers of America's atomic clock, which gives us the official time.

Lowe is leader of the atomic standards group, which builds the atomic clocks designed by a bunch of fellow doctorate physicists. As a quick aside, how accurate is the atomic clock? "If we set the present clock we have running at the time of Christ's birth, it wouldn't be off by 1,000th of a second yet," explained Lowe, 48. "It will neither gain nor lose a second in 30 million years."

And man's quest for accuracy brings us smoothly back to leap year. Lowe says it turns out that, rather inconveniently, the earth's passage around the sun and the planet's own daily revolutions don't take 365 days precisely. The actual yearly figure is 365.2422, give or take. So we need to periodically add some time to stop the seasons drifting out of whack.

The ancient Egyptians, who inherited their 360-day-long calendar from the even more ancient Phoenicians, weren't too bothered by this precision stuff. But they did try to make amends by adding on five festival days at the end of each 360-day year.

"Basically, they just partied for five days," Lowe said.

This wasn't good enough for Julius Caesar who, after 4,200 years of the Egyptian calendar and its vagaries, decided, in 46 BC that the might of Imperial Rome could do better. Caesar, who probably would have been better off paying more attention to the Ides of March, consulted his mathematicians and decreed the new "Julian" calendar would henceforth have 365 official days, with a leap year every four years to deal with that annoying leftover fraction.

Why did Caesar add the leap day to February? "At that point in time, March was the very first month of the year, and February was the last month of the year," Lowe explained. "So it made sense. They ended up naming the calendar after Caesar, and they named July after him, too."

But that awkward fraction that isn't quite a quarter day meant that adding up four quarters and calling it leap day every four years was adding too much time over time. By the reign of Pope Gregory in the 16th century, Easter was creeping away from springtime, and the calendar was off by 10 days and rising.

The Vatican's mathematicians fixed it by decreeing that, from 1582 onward, leap day would fall every four years except for those years divisible by 100, unless that particular year also was evenly divisible by 400. Got that? So 1700, 1800 and 1900 were not leap years, but 2000 was. This regulates the number of leap years and stops us adding too much overtime to the calendar. Almost.

"Even with these new rule changes, we'll still be off one day in every 3,300 years," said Lowe, who relishes details. "So, if man survives, we'll have to have another leap day thrown in to bring us back into sync once again."

The problems of getting back into sync in 1582 makes future adjustment problems look like child's play, however. To correct the drift built up since Julius Caesar's time, the now "Gregorian" Calendar decreed the adjustment would be made in October 1582; people who went to bed Oct. 4, 1582, found themselves waking up Oct. 15.

Aside from the sheer logistical feat of coordinating this across the then Catholic world, there were Protestant countries like England who would have none of this Popish plot to steal time. But by 1752, when the English calendar was off by way more than 10 days, the Protestants stopped protesting and made the jump: Sept. 2, 1752, was followed by Sept. 14, with the English colonies in America changing at the same time.

"It caused some funky things," said Lowe, who says workers back then rioted, believing they were being cheated out of two weeks' pay. "George Washington was actually born on Feb. 11, 1731, according to the Julian calendar in use at his birth. But we now celebrate his birthday as Feb. 22 because we had to jump those extra days and make other adjustments associated with adopting the Gregorian calendar."

One Central Illinois man who has worked on clocks dating back to Washington's era and always has time on his hands is Jerry Watkins, who runs Watkins Jewelers in Clinton with his wife, Marilyn, and son, Steve. He's marveled at beautiful antique clocks with complex wind-up calendar mechanisms designed to compensate for leap year, and Watkins said the care and craftsmanship lavished on old timepieces reflects the value we place on the commodity they measure.

"We're just obsessed with time," he added. "And that's why you have the fascination with time machines."

But Watkins doesn't mean clocks. He's talking of fantasy machines that would let you cheat days, months, years and leap years by traveling through time. Watkins believes that, one day, physicists will turn fantasy into reality and invent a device that would let us slip the surly bonds of the present and go into the future or the past. Personally, he'd go back.

"I would like to meet Christ," he said. "Wouldn't that be the most glorious thing a person could do?"

Casey Watson, assistant professor of physics and astronomy at Millikin University, doubts Watkins will get his wish. He says physics shows few avenues where time travel into the past would be possible, citing the grandfather paradox: you go back into history 70 years and kill your own grandfather when he was a boy. How do you now exist on Feb. 29, 2008?

But leaping into the future to Feb. 29 in the year 3200 might be in the cards. Watson said that Einstein's special theory of relativity says that if you can accelerate toward the speed of light, time for you would slow down dramatically. "You'd be gone for what seemed like 10 years or so, but maybe more than 1,000 years would have passed on Earth by the time you get back," he explained.

And despite his skepticism for the prospect of historical excursions, Watson said he actually can time-travel into the distant past anytime he wants, and you can, too - just look up at the stars. Because distances in space are so great, they're measured in leaps of time expressed as the distance light (traveling at 186,000 miles per second) can cover in a year.

Recently, Watson's been watching a swollen, dying star called Eta Carinae, which ballooned to 100 times the mass of our sun and is about to blow up. At least it was, more than 5,000 years before the birth of Christ.

"Eta Carinae is 7,500 light years away from us," he said. "So we're seeing it as it looked 7,500 years ago. Light is effectively our time machine."

Tony Reid can be reached at treid@herald-review.com or 421-7977.