Time Boundary
A time boundary is the limit you set on how much of your time and energy you give away. It protects your hours, your rest, and your right to say a request does not fit.
Your manager asks for a favor at 6pm and you hear yourself say of course while your stomach drops. That is a time boundary collapsing. It also looks like answering messages the moment they arrive, agreeing to meetings you have no room for, and treating your own plans as the first thing to cancel.
People who please tend to price their time at zero. Other people's urgency feels louder than your own schedule, so your evening, your day off, and your unscheduled hours get spent before you have decided anything. The cost shows up later as resentment, the quiet bill for time you gave away without choosing to.
A time boundary can be a single sentence. I can do this by Friday, not today. I am not free this weekend. Let me check before I commit. The pause between the request and your answer is where the boundary lives, and you are allowed to take it.