I went to see Alk3 at the Metro for their New Year's show back in 2007. We got there at 10am for a 10pm show and were the first in line. No one else showed up until around 1pm. If you're serious about being one of the first few in line I wouldn't show up later than 1pm to be safe.
Thank you! From what I’m getting from asking around, the general consensus seems to be between noon and 2 pm the absolute latest.
Looks like I’m going to be freezing my ass off for at least 9 hours! Haha.