The astronomical difference a Leap Day makes: We'll have the earliest spring since 1896

The birds have been chirpier than normal for a February, the snow drops and daffodils are showing no fear, and when was the last time you saw salt brine on a road near you?People in the U.S. have a 100% chance of having their earliest spring in 124 years, arriving officially this year on at 11:50 p.m. EDT on March 19.Not only do we get a Feb. 29 in this leap year, but spring gets to leap forward on the calendar, and for that we can thank Julius Caesar, who was slightly off the mark (but who was going to correct him?); Pope Gregory XIII, whose calendar we use today; and the relentless eccentric...