The New York City Subway system has lettered or numbered route designations. The , , , , , , and trains are fully local, making all stops. The , , , , , , , , , and trains have portions of express and local service. The train normally operates local, but during rush hours it is joined by the train in the peak direction. Both run local, express or skip-stop on different parts of their route. The and are fully local, but during rush hours, express variants of the routes, designated by diamond-shaped route markers, are operated alongside the locals in the peak direction. The has portions of express and local service, but during rush hours, an express variant of the route, designated by a diamond-shaped route marker, is operated alongside the local in Brooklyn in the peak direction. The letter is used for three shuttle services: the Rockaway Park Shuttle, Franklin Avenue Shuttle, and 42nd Street Shuttle. The subway normally operates 24 hours a day with five different service patterns: rush-hour, midday, evening, weekend and late-night. Each service has a table in its article to show what tracks are used and when. This article lists all the current services, along with their lines and terminals and a brief description; see Unused New York City Subway service labels for unused and defunct services. In the New York City Subway nomenclature, numbered or lettered "services" use different segments of physical trackage, or "lines". The services that run on certain lines change periodically. Time periods The New York City Subway is one of the few subways worldwide operating 7 days a week, 24 hours a day, every day of the year. The schedule is divided into different periods, with each containing different operation patterns and train intervals. The MTA defines time periods as follows; these are used in articles (sometimes abbreviated by numbers in superscript or the symbol indicated): (1) rush hours – 6:30 a.m. to 9:30 a.m. and 3:30 p.m. to 8:00 p.m., Monday–Friday (1a) rush hours in the peak direction (toward Manhattan in the morning, away from Manhattan in the afternoon) (2) middays – 9:30 a.m. to 3:30 p.m., Monday–Friday (2a) middays in the peak direction (2b) middays in the non-peak direction (3) evenings – 8:00 p.m. to 12:00 a.m., Monday–Friday (3a) early evenings – 8:00 p.m. to 9:30 p.m. (3b) evenings in the peak direction (3c) early evenings