Is it a mission or an Expdedition?

Over pints of grog GutZ and I were discussing possible destinations for upcoming fishing trips wherein I discovered the difference between a fishing mission and an expedition. As in going to Forks can be a mission for us, but the Columbia river is an expedition. Here is the key:
Fishing Mission: A weekend, leave Friday after work and come back Sunday night.
Fishing Expedition: Take a day or two off work as in a 3 or 4 day weekend.
Fishing Vacation: More days than an expedition.

Okay, I thought this would make an intereting post to see how everyone else defines the trips.

Bye the way, my girlfriend wanted to know why we couldn't just go for a day. After explaining the above to her, she is now thankful I am just going on a mission, and not an expedition! I wonder how long that will last.