Astronomical summer officially arrives in the Northern Hemisphere — amidst a heat wave — at 4:51 p.m. ET. It's the earliest start to the season since 1796, thanks to quirks in the calendar.

We get a leap day only every four years. How will you spend it? Here's some inspiration from people celebrating all sorts of personal milestones — and those who just want to enjoy their extra day.

Why do we have leap years, and what are we supposed to do — or not do — with our rare extra day? NPR's Morning Edition spoke with experts in astronomy, history and economics to find out.

Will you be celebrating a birthday on Feb. 29, or have other fun plans in the works? NPR wants to know how you'll be spending your leap day.

Winnie Madikizela-Mandela, a leader in South Africa's anti-apartheid movement and ex-wife of the late Nelson Mandela, died Monday . She was 81. On...