I was leaving a parking lot when I saw a man jump out of his car, wave his arms, shake his fists and rant at a woman in a car that had nearly collided with his. Given the particulars of the near miss, it’s hard to say whose fault it would have been had they connected, but I can tell you whose side I would have taken.

The guy was — and I mean no disrespect whatsoever when I say this — a bad-tempered, ill-mannered meathead. I rolled down my window and asked as gently as I could, “A little cranky, are we?”

No, I didn’t do that. Instead I decided to channel my dismay at the incident into educating grouches everywhere that the proper time for public displays of grumpiness is Oct. 15 and only Oct. 15. That’s National Grouch Day, a day set aside to honor everyone’s favorite grouch, Oscar from “Sesame Street,” and to celebrate, or at least tolerate, all the grouches we know, possibly including … well … us.

If there’s a grump in your life, allow them to be as irritable as they want to be on Oct. 15. Say nothing while they whine, complain and generally wallow in their misery all day long. But come Oct. 16, tell them you and everyone else are sick and tired of it so they ought to just knock it off right now. That should cheer them up.

If it doesn’t — and it might not — try the following tips I found on that font of all wisdom, the internet.

1) Gently explain to the grump that exercise causes our body’s natural pharmacy to release endorphins which are associated with feelings of happiness. Tell him he should take a long walk…off a short pier. Then say, “Haha! I’m joking! Isn’t it great? Laughter helps cure crabbiness too.”

2) Give her a stick of gum. Apparently the repetitive action of chewing gum can be soothing. If that doesn’t do the trick, offer her a chew toy. 

3) Tell him doing something nice for someone else is a sure cure for crankiness. Then tell him what you’d like him to do for you.

4) Give her chocolate. Eating chocolate makes some people happy. I’m one of them. So if she doesn’t care for chocolate, she should see rule number three and give hers to me. Then we’ll both be happy.

5) Pets make people happy. Try giving the grouch a puppy.

6) Decluttering has a calming effect, so tell the cranky person his house is a mess and he’d feel better if he’d just get himself organized. Who doesn’t love to hear good advice?

7) Tell her to smile. The simple act of smiling can cheer us up. So the next time you encounter a crab, tell her as sweetly as you can to turn that frown upside down. It will either work or she’ll punch you.

8) Tell him that rearranging furniture is a great day brightener. Changing an environment can help us feel refreshed. If he doesn’t want to move his furniture around, tell him he’s welcome to move yours.

9) Play her some music. Music can turn a bad mood around. If there’s no music available, sing to the cranky person. If that doesn’t make her feel better, it may at least make her leave you alone.

10) Encourage the crabby person in your life to count his blessings. Explain that if he keeps thinking about everything that’s wrong, his negative emotional state will continue. Certainly, he has much to be thankful for. For one thing he’s got you to advise him.

Dorothy Rosby is the author of ’Tis the Season to Feel Inadequate; Holidays, Special Occasions and Other Times Our Celebrations Get Out of Hand and other books. Contact her at www.dorothyrosby.com/contact.