Why do sports commentators frequently mention "tonight" in games when it is clearly a afternoon game?

Question

According to Webster night time is: 1 : the time from dusk to dawn when no sunlight is visible.

http://www.webster.com/dictionary/night

When I see light in the background (like coming down the ramp in a basketball arena) - and it is 2pm ... I wonder if these guys are in the dark?

Answer 1

Probably just a habit.

Answer 2

Dear depending when a game starts on Monday and when Monday occurs you said today match instead of match in the morning, so it is usual to say Today for morning and after noon and tonight for evening and night.