Not only will it be 6pm but access to the rest of the stadium won't be until 7pm. Maybe not worth it to get ther too early.
I believe this is incorrect for two reasons.
(1) The Nationals' Twitter feed says that ALL gates will open at 6:00 PM. That means they wouldn't be able to keep you out of the rest of the ballpark.
(2) Yesterday the gates opened at 1:30 and I entered via the home plate gate at 1:40 and then headed anti-clockwise around to the outfield to watch BP and take some pictures. The concession stands looked open, although the workers may have been unprepared to serve people. One of the Senators Sausage places had a lot of half-smokes ready to go.....
Based on all that, presumably we get the run of the place at 6:00. I'm shooting to be down there sometime between 5:00 and 6:00 based on traffic and parking concerns. Told Ms1995hoo she can take the Metro when she gets off work at 5:30 and she readily agreed, provided I come by her office on the way to retrieve a few things she doesn't want to carry with her so I can lock them in the trunk.
BTW, National Anthem tonight is to be the Army Chorus Quartet. They've performed at Caps games several times. Bob McDonald and Caleb Green are members (those of you who attend Caps games should recognize those names).