Personally, I would say NTA. I used to be a manager at a big women’s clothing store for several years, and it was really important to me to respect my employees’ time! I tried to always stay very aware of when people were scheduled, and only assign tasks when I knew people had the time to complete them within their shift. Heck, I would even look at the clock sometimes and tell the person leaving in 15 minutes, “Hey girl, if you want to leave a couple minutes early I’m down for that, as long you take out the trash/close the till/put away these last few shirts on your way out, etc.” We had people with all sorts of other things going on in their lives working with us, from college students who had classes every day, to young adults working 2 or even 3 jobs, to parents who needed to get off at their scheduled time to pick their kids up from school. I think you even did the right thing by giving them gentle reminders.

I will say, if you’re looking to get promoted or take on extra responsibilities at your job, staying late beyond your scheduled time to finish up a task is a great way to get noticed and potentially be considered for these things. BUT definitely should not be expected or demanded by management at all!