Mahlzeit!

There’s really only one German word you need to learn in order to work in a German company. Though I never speak English at work, everyone knows how to, and most have dealt with visiting co-workers and customers whose only common language is English. English also turns up in some random places at work: "Junk E-Mail" apparently has no translation, and titles of projects are often in English. (For example, I'm working on "Move Ahead," for SAP implementation.)

But regardless of your German skills, the word Mahlzeit (literally: “meal time”) is very important. At first I thought it was just a synonym for “bon appétit” (they also say Guten Appetit) – used when someone is beginning to eat. But it’s much more than that. Imagine it’s 11:30 and Georg is the first in line for lunch. He’ll exchange a “Mahlzeit” with the cook and the co-workers who first sit down with him, as well as those who come later on. They’ll all say it again when Georg leaves the Kantine, and he’ll continue to exchange it with people who see him coming back from lunch or with people on their way to lunch. In fact, he’ll say it to anyone he sees in the hallway for the next 2 hours, just in case they’re coming to or from lunch.

I've had to work on remembering to say "Mahlzeit" since noticing how frequently it's used. I see it as a challenge to try and tell someone "Mahlzeit" before they can say it to me. I want to expand it even more and say it to people who look hungry or as a subtle suggestion that someone should give me a snack. Any suggestions as to other relevant contexts would be much appreciated.

P.S. Another word I've heard a lot just made sense to me today: Feierabend (literally "celebration evening"). Feiertag means holiday, so I thought Feierabend meant taking the evening off, or leaving work early. This was confusing because co-workers would take about "doing a Feierabend" when someone left, even if it was already 7:30 or 8 PM. Wow, that's quite the evening off! How will you manage to fill up your remaining hour of daylight? But apparently it's more like "to be done for the day" or "to call it quits."