From Custom Solutions of Maryland:
Time Clock was developed to help the user keep track of time spent on a project and remind the user when to take breaks. The user can set the desired time between breaks. If the user is not ready to take a break when prompted, he can postpone the break before he is reminded again and this time is also settable. A log is provide. Settings, log and running time are saved between sessions.
What's new in this version:
Version 2.3.0 is compatible with Yosemite's default security.