If you have co-workers, you probably have at least one Cranky Co-Worker. You know who he or she is. Walking around carrying the weight of the world, either sighing disdainfully every five seconds or complaining loudly to any and all who will (or won’t) listen, he or she is the reason that you either drink extra coffee, clock out as soon as the clock strikes quitting time, or simply avoid said person at any cost.

To be fair, we all have our cranky days. You wake up on the wrong side of the bed, you get a migraine, you battle your kid over everything from breakfast to not wearing his Halloween costume to school…whatever. But most of us can get past the doldrums or cantankerous crabbiness and move on with our days—if not today, then we’ll try starting over tomorrow.

Not the Cranky Co-Worker! He or she isn’t satisfied until complaining about everything from the broken copier to the rain (And aren’t you sick of people complaining about rain? Be grateful for it, for crying out loud; some people pray for rain—even perform elaborate ritual dances to coax it into existence! Eat your veggies and Cheerios and other fruits of rain and be grateful. And buy an umbrella already.) to the “boss’s favorite” has all been completed and checked off before break time.

And as much as I’d like for Cranky Co-worker Day to be the day you tell His or Her Holy Crabbiness to knock it off already, it’s supposed to be the opposite—the day you give him or her a wide allowance to simply be cranky.

If you don’t want to participate, I don’t blame you; it would be like aiding and abetting, right? But perhaps it would be worth it to see from his or her perspective for a day. Perhaps he or she has something going on at home that you aren’t aware of—a sick relative, a rough home situation, whatever. Of course, some people are just pessimists, so you’ll never know until you ask (or do a little digging, if you’re into that sort of thing).

You could also try cheering up said cranky person. Again, you’ll never know if his or her incurable crankiness could shift with a simple smile or kind act unless you try. I’m not saying it’s your job to do so, but if you feel like it, why not make the gesture? Maybe it’ll make your work day go by a little more easily if you do.