PC Chrono is a freeware timer, stopwatch and clock utility. It is also distributed as a part of 5-cow rated WakeMeUp! Alarm Clock.
Its main features:
Countdown Timer capable of .mp3, .ogg or .wav file Playback on completion. S1 / S3 (suspend to RAM) / S4 (hibernate) resume is supported;
stopwatch;
12/24 Hour Clock;
customizable voice notifications for all modes (timer, stopwatch and clock).