I blogged yesterday about a Department of State (N.Y.) government website page that only accepts information during business hours. You offered several other similar examples (many of them government sites as well) and possible explanations. We also received, via comment and e-mail, an explanation from Edison Alban, press officer for the D.O.S. (BTW, his name could be considered a pretty good aptonym, since Albany is the capital of New York.)
He begins by objecting to the post, particularly the headline, which was "This Website Only Open During Business Hours":
The New York Department of State’s Division of Corporation website is accessible 24 hours a day, 7 days a week. The Division of Corporation does not shut down its website during non-business hours.