The Prague tram (streetcar) system is the largest tram system in the Czech Republic, consisting of 140 kilometres of track, over 900 tram cars, and 33 lines with a total route length of 540 km. It is operated by Dopravní podnik hlavního města Prahy a.s., a company owned by the City of Prague. The system served 356 million passengers in 2008. The first horsecar tram line was opened in 1875, the first electric tram ran in 1891.
As of 1 March 2011, the Prague tram network includes:

24 day routes (numbered 1 to 26 [excluding 13 and 23]),
9 night routes (numbered 51 to 59) and
1 historical route, number 91 (in service between April and October, weekends only).

The day lines run from 4:30AM until 1:00AM (Su – Th) 1:30AM (Fr, Sa) the next day. Most of the lines run everyday from early morning to late night. Some lines also only run at selected times (usually workdays) and/or rush hours.
[edit] Night trams

Night trams operate between midnight and 5:00 or 6:00. Their routes are different to the daily ones, since in the night the trams have to substitute for the Metro. All lines converge at Lazarská in the city centre, although other interchanges exist. At Lazarská, passengers can change between all routes within 5 minutes, although individual services only run once every 30 minutes. Trams operating on the night lines start their shifts at about 8:00 PM on normal day lines, changing their routes at midnight and returning to their depots at the start of normal operations.