I called off work for a movie with me and dad but not for a date because me and my girlfriend didn't confirm it she talked to her mom and said her mom basically said yes but that wasn't confirming it to me so i never took the day off she's pissed at me for that and because I didn't tell my mom because nothing was confirmed it was just an idea to me at that point.
First off, calling off work to go to a movie with anyone is not acceptable. Employers count on their employees to show up. I wouldn't count on being employed long if that is a common practice.
Secondly, if you made tentative plans with someone, you call and confirm them. You don't just not show. That is just plan rude.
Your girlfriend is out of line in being mad at you.
Secondly, it is not a good practice to skip work for play. It only takes one time getting caught for it not to feel good when you go back to work and realize that your boss knows what you did. He/she might have the tendency to not believe you when you are actually sick and have to call in.
Lastly, when making plans with someone, always confirm / check back so that everyone is on the same page and knows what's going on.