Hi Ruby. Thank you for reaching out to us with these questions.

I'm really sorry to hear about your rough day at work. I am not sure why he seemed mad at you. But my guess is, if he called you before your scheduled time, it's possible that he was stressed out about the shortage of staff. The frustration may not have been personally directed at you.

If this work environment is too stressful for you, maybe you can eventually switch to another workplace. But until then, you should come to work on time, because that is your responsibility.