Interesting. I know the Nationals asked the scheduling committee not to give them day games at home during the weekday. I think it was because the Metro was (and still is) unable to handle the influx of game attendees that would use the system during the work day. Any idea why they wouldn't be able to play the games at night? Is there some other team(s) that also uses Wrigley?
EDIT: nevermind, found it this on Wikipedia:
The truth of the matter is, the Cubs have to petition the Chicago City Council to play more night games.
In the late 70s and early 80s, when the Chicago Tribune Company acquired controlling interest in the Cubs, they started making noise about installing lights. The Wrigley family had run the Cubs more like a hobby, and had really never seriously considered installing lights. Residents of the Lakeview Neighborhood in Chicago, where Wrigley Field is located, formed a group to oppose the installation of lights at Wrigley -- "Citizens United for Baseball in the Sunshine" or CUBS. The Chicago City Council passed an ordinance prohibiting nighttime outdoor athletic events at facilities that exceeded a certain capacity (thus allowing high school and college sports to mostly go on unabated) and exempting the White Sox and Bears home stadiums through a grandfather clause. The whole 2:20 and 3:00 start times came from those days -- the Cubs brass scheduled games as late as possible to attract more of the business and potential night-time crowd, while getting in enough baseball before the sun set.
So when the Cubs originally got night ball, it was for an extremely limited number of games to appease the neighborhood residents. They have gradually gotten more and more of them.
And here's hoping the Nats do some major Ass kicking this weekend. Lordy, Lordy! I do hate those Scrubs! If the Cubs were playing the Taliban, I'd have a hat on with a "T" on it! Go Nats!