Wanna know just how fast time flies?

Here’s some news that clocks it at a staggering SST velocity: Only yesterday, it seems, Green Day’s Billie Joe Armstrong was an angry young green-haired man, writing about cute girls he saw — but was too shy to address — in the high school library.

Now, he’s a father who just produced the upcoming debut from Emily’s Army, an Oakland proto-punk quartet that features his own now-teenage son, Joey Armstrong, on drums. The album is due out June 14.

Pretty freaky, right?

Ranging in ages from 15 to 17, the lineup also includes brothers Max and Cole Becker, on bass/vocals and guitar/vocals, respectively, and guitarist Travis Neumann. They took

their moniker from the their 5-year-old cousin Emily, who was diagnosed with cystic fibrosis in 1998, and they’ve even set up a fundraising organization for her under the same name.

On May 21, they’ll be playing a cystic fibrosis benefit called Great Stride on the Huntington Beach Pier. Once the “Man, I’m getting old” shock wears off, it’s great to hear yet another young generation flying tthe snot-nosed punk rock banner, in bratty anthems like “F-Word” and “Some Call ’Em Girls.” And believe it or not, Emily’s Army has already been touring up and down the West Coast for two whole years.

For the charity, check in at www.emilysarmy.com; for the band: www.myspace.com/emilysarmy101.