If you are an asshole, apologize.
The longer that you wait to apologize, the more apology that’s due. Sorry, you thought leaving it for several days or weeks meant that the hurt you caused would lessen? It doesn’t work that way. When you leave an apology for several days or weeks, it only causes more distress and unease for the person you aren’t treating fairly.
If you think that you have free reign to be an asshole so much as you damn well please, you need to realign your perspectives. You also need to ask yourself why you’re so okay with treating the people in your life so poorly. I think some soul searching is on order, on your behalf.
On the flip side…
If you are someone at the receiving end of an asshole’s shiteous behaviour, don’t let them off the hook.
An apology is due. Expect it. No matter how many days go by, do not tell yourself they’re sorry without them telling you they’re sorry. Do not make excuses for them. There are no excuses for unfair treatment. Full stop. Not if they’re stressed, not if they’re sad, not if they’re scared, not if… anything. You deserve an apology. Hold their feet to the fire until they recognize that they’re being an asshole and that it’s not fair to you.
“I’m sorry you feel that way” or “I’m sorry you are offended” or “I’m sorry you think that” are not apologies. Someone needs to feel bad about their own behaviour, not for the way their behaviour was interpreted.
“Yeah well, imagine how I feel” is not an apology. It feeds a notion that if someone knew how an asshole felt, they’d be more accepting of the behaviour. The truth is, it doesn’t fucking matter how an asshole feels. No feeling warrants someone being an asshole. Also, they’re probably already well aware of how an asshole feels.