Metallica have ended their mysterious countdown clock, revealing that they will be playing two headline sets at five different US festivals in 2020.

Earlier this week, Metallica fans found themselves thrown into a myriad of questions after the thrash icons launched a cryptic countdown clock on a new website.

Called MetallicaXX, the site consisted of little more than a timer counting down until 12pm AEDT on Thursday. Of course, suggestions as to what it may be came thick and fast, with many fans looking at the inclusion of the ‘XX’, to mean that a 20th anniversary celebration of something could be on the way.

With the group’s S&M² concerts hitting theatres yesterday, others believed the announcement may indeed be related to the new gig. Now, after days of waiting, we finally have our answer.

The band are set to headline twice at Epicenter Festival, Welcome To Rockville, Sonic Temple, Louder Than Life and Aftershock — playing two different sets over two nights.

The 10 shows over five festivals are the product of a partnership between Metallica and Danny Wimmer presents. “Metallica isn’t just another headliner. When Metallica takes the stage, it’s an event. It’s an experience,” Wimmer shared in a statement.

“I can’t wait to bring the biggest band in the world to the biggest rock festivals in America.”

In related news, Aussie metalheads were undoubtedly devastated last month to learn that the highly-anticipated tour from Metallica would not be going ahead as planned.

Originally slated to kick off next week, the band revealed that their upcoming dates would be postponed while frontman James Hetfield entered a treatment program in order to confront his struggles with addiction.

At this stage, there’s no word as to when these dates will be rescheduled, though proposed tourmates Slipknot say they’re hoping to bring their live show down to Australia regardless at a similarly undetermined date.