[1] The subway normally operates 24 hours a day with five different service patterns: rush-hour, midday, evening, weekend and late-night.
In the New York City Subway nomenclature, numbered or lettered "services" use different segments of physical trackage, or "lines".
The MTA defines time periods as follows; these are used in articles (sometimes abbreviated by numbers in superscript or the symbol indicated): Other symbols are derivatives and are defined based on the rules above: Lines with colors next to them are the primary trunk line of the corresponding service; they determine the color of the service bullets and diamonds, except shuttles, which are dark gray.
The following lines run in special service or after sporting and other events: The schedule offers trains every 3 to 5 minutes on the most used sections during rush hours.
[note 3] See New York City Subway nomenclature for a complete explanation; this is just a table of when each service has existed (and been signed for the public).