Tomorrow is February 29, a rare day. This is a leap year, so an extra day is added to February.

There is science behind the need for a leap year. The length of the year is defined by the time it takes for the Earth to make one trip around the sun. It takes about 365 days to do this. There's a fraction of a day left over each year, so the occasional leap year helps to even it out.

So what would happen if we didn't have a leap year? That fraction of a day would accumulate, and soon the months and the seasons would be out of sync. Winter in July? Summer in December? Leap year keeps the months and the seasons coordinated. That helps us to plan for the future and understand the past. Your highest heating bill in our hemisphere will always be in January; it's time to plant in May and harvest in September . . . well, you get the idea. It just makes everything make more sense.

Happy Leap Year!