Summer solstice 2012 today,Longest day of year on 20th June

This year's summer solstice takes place today a day earlier than it's been for the past three years, due to leap year 2012—this February got an extra day,

 

to keep our calendar year of 365 days in sync with the astronomical year,

 which is about 365.24 days.The exact timing of the summer solstice changes from year to year,

"but there's a bigger jump when you have a leap year," an astronomer at the Adler Planetarium in Chicago explained name Mark Hammergren.