Punctuality is the fact or habit of arriving, happening, or being done at exactly the time that was arranged. If a train has good punctuality, it comes when the timetable says. If a person is known for punctuality, they are not late. It is a slightly formal noun; in everyday talk people more often say “She’s always on time” than “Her punctuality is excellent,” but schools, workplaces, and transport reports use it a lot. In some places, being a few minutes late is normal; in others, punctuality is treated as respect. The word is about the clock, not about manners in general, and not about commas and full stops.