Oops...I think I just pissed off my boss...Can you help?

If you have a reputation of always going the extra mile and staying to finish things, then I wouldn't worry too much. I would apologize if SHE misunderstood you to be rude, but be firm about leaving on time. You must set boundaries and have your own life outside of work.

Well they can't fire you for not working over time. However, when you were hired on was it explained that one of the requirements is occasional overtime? If so then the worse they can do is write you up but its still not grounds for dismissal.

Next time you're to help on a project just explain that you can but you have plans and need to leave by: _______. So then it is clearly understood of you desired departure.

Unless you have extremely important plans, you should've stayed to help. In addition, to score extra points, you should have said, "I'll be happy to help you out. Just let me make a few phone calls that'll allow me to cancel my plans for this evening." One, you're helping her out ( a good employee) and two: You're making her feel guilty about disrupting your plans for the evening. In the end, she'll owe you one.

She can't fire you for that alone. Just explain to her next time that you were ready when you were supposed to be, and shouldn't be expected to wait forever. Then offer to help on another project.

Go talk to her tomorrow, apologise if u feel u were a bit rude. dont apologise for wanting to leave on your time, just explain it was very important for you to leave this specific day. Set your limits in a nice way, i am sure she will respect it.

i would go to her superior and explain the situation. you had plans made. she didn't do her part and now wants to force you to work o.t. i think her boss will have a small talk with her first thing in the morning. don't stay!!! go home at regular quiting time.

Work can be so stressful im glad i get out in half hour, good luck

Probably nothing you can do except apologize although she sounds pretty inconsiderate to do you that way.