we use .wav Timers in Quake 2,they are used since ages,they are allowed in Leagues/tournaments but they are banned in the American servers.
to use the timers,you have to download a .wav file and put it in your pak ( or your q2 folder ) and bind a key for it,for exemple if the file name is weapon30.wav,you type in your cfg or in console: bind <key> play weapon30.
timers are considered cheating in other quake games tho.