If your birthday falls on June 30, you can celebrate for a wee bit longer this year!
The last day of June this year will get an extra second after the Paris Observatory announced it was adding a leap second to clocks.
Dials will read 11:59:60 on June 30 as clocks hold their breath for a second to allow the Earth's rotation to catch up with atomic time, experts said.
Atomic time is constant, but the Earth's rotation is gradually slowing down by around two thousandths of a second per day.
Scientists at the International Earth Rotation Service in France monitor the Earth's rotation and tweak time where necessary.
Software companies are already bracing themselves for problems. When the last leap second was added in 2012, several companies reported crashes and there were also problems with programmes written in Java, the Telegraph reported.
"The Earth is slowing down a little bit," said Nick Stamatakos, the chief of Earth Orientation Parameters at the US Naval Observatory.
"They add an extra second to something called UTC (Coordinated Universal Time) in order to make sure the rate of UTC is the same as atomic time," Stamatakos said.
The first leap second was added in 1972, and it will be the 26th time it has been added to clocks in history.
Adding the leap second will mean that at 11:59:59pm on June 30 for one second clocks will read 11:59:60pm.
"For that day [June 30] there'll be 86,401 seconds, instead of 86,400 seconds. The length of the day for you and I and everyone on the Earth will have an extra second," Stamatakos added.