TIMEBOX - An advanced timer for professional meeting facilitators
MetaClock.com - MetaClock is an Online Alarm Clock that can play YouTube videos and uploaded MP3s as an alarm tune. It supports Chromecast which means you can turn your TV or stereo system into an alarm clock. No installation is needed, it can also work offline.
KukuKlok - Kukuklok is a free alarm clock available online and offline.
Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
Online Stopwatch and Timers - Sometimes everybody need to count time for some reason.
Music Alarm Clock - Music Alarm Clock is an alarm clock that uses the song you intend to play before you fall asleep as an alarm that wakes you up.