I’m always unpleasant whether it’s a good day or a bad day.

Not really but look up cantankerous curmudgeon.

I'm only human. I have been on both sides of this one.

Generally no, it gives me the right to keep to myself until I feel better, or to sit on it and spin. It's a likely explanation but not an excuse.

But it depends on how unpleasant vs how bad of a day really; it's all relative. A lot of bad days could be bad enough to fully excuse some minor levels of impatience, anxiety, or being unwilling/able to feign cordiality, oblige solicitors, or abide obnoxious small talk. If by unpleasant you mean your behavior has devolved into recklessness, or actionable beligerence then no, your day probably wasnt bad enough to warrant that unless you're actively being assaulted.

This is on topic...

Today was total bullshit. Still, I've shut my trap and kept my naturally aggressive nature to myself. It's bad enough I got treated like a diaper today. It's no good speaking that shit into others.

Yes. However, it doesn't give one freedom from the consequences of said unpleasantness. There's a difference, though, between 'unpleasant' and 'cruel' or 'mean-spirited.'. I try not to be deliberately hurtful, but I'm not going to force myself to be sunshine and puppies 24/7, either.

I reserve the right to be unpleasant irrespective of the quality of day I've had.

No. It gives you no rights what-so-ever. When one feels a bad day provides the right to be a jerk it's important to understand that a jerk just feels like they have justification to be a jerk. To the rest of the world it's just a jerk acting like a jerk. Jerks everywhere are just looking for excuses to openly act like the jerk they are and feel that the have a "free pass" at being that jerk (as if there is such a thing). If one is not a jerk then they just temporarily keep their mouth shut.

Absolutely not, also, I feel being unpleasant just lengthens your misery.

Only to those directly involved it making it the bad day...

Absolutely not, under no circumstances. Why should others have to endure the slings and arrows of outrageous fortune (thanks WS)?

Nope -- unless it's to the person who was the cause of the bad day.

Sorry, the politically correct answer is no but the real answer is yes. You "get" to be unpleasant or anything else you "want" to be. You can even be unpleasant if you had a good day. Last I checked there is no "Bill of Unpleasant Rights"

I try not to be unpleasant. I can see where it might make one grumpy.

I think if your around the person that ruined your day you have the right to be a jerk towards them.

existing gives you the right to be unpleasant.
More to the point, no one is under any obligation to be pleasant.

My landlord is a super sweet and always smiling compulsive lieing manipulative control freak, who shares (gossips) the personal situations or lives of the tenants to all of we tenants. And she feels as a landlord, she deserves the "truth" regarding any question (interrogation) she puts forth. I was ill with a low grade fever this weekend and indeed having a bad day when I found myself dealing with her sweetly disguised manipulative insinuations, and I was very unpleasant towards her. . She deserved my OWN insinuations and she was thus provided a tablespoon of her own medicine. Sometimes people who go around slapping others, need to be slapped right back.

To who ?

you have no rights

Waking up gives you the right to be un-pleasant.

You have no right to be shitty to anyone who isn't being shitty to you.

You have the right to be and act how you want no matter how your day is as long as you don't break laws while doing it.

No! I am fortunate to be able to switch behaviors in a heartbeat.

I believe you have every right to feel the way you feel. How you act in response to that feeling is up to you, but other people also have every right to respond to your mood appropriately. You may feel justified in your actions but you likely won't win any friends if you are too grouchy. Try as I might, my feelings get the best of me occasionally. Sometimes I just need to vent, even though I know I will regret it later.

it makes it hard to be pleasant. So being unpleasant is easier when you have a bad day