This Bugle call is played in the military forces at the end of the day, particularly in the US. It has a longer cousin called The Last Post which is used in a similar way. Both of these calls are also played at military funerals. There are a variety of bugle calls used at the start of the day including The First Post, Rouse or differnet calls called "Reveille" (e.g. Reveille (UK), Reveille (US) and Charlie Reveille). See the links at the left to download the sheet music or audio files. More bugle calls are listed in our article about the history and cultural impact of Bugle Calls
The image below is the first page of the sheet music, and here you can download the full sheet music for Taps (bugle call) in PDF format.