News Billie Joe Announces Green Day Tour Post-Rehab By Jackie Willis 8:17 AM PST, December 31, 2013 Getty Images After entering rehab in September, Green Day frontman Billie Joe Armstrong thanked his fans for their support and revealed some exciting news on Sunday, Dec. 30. The musician wrote on Instagram that he was grateful "for all the love [and] support you've showed for the past few months." "Believe me, it hasn't gone unnoticed and I'm eternally grateful to have such an amazing set of friends and family. I'm getting better every day."Armstrong, 40, added, "So now, without further ado, the show must go on. We can't wait to get on the road and live out loud! Our passion has only grown stronger. ... Green day tour in March." The singer entered rehab two days after an on-stage rant at the iHeartRadio Music Festival in September.