Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.
Absence - Employee vacation tracking system
RescueTime - Time management software that shows you how you spend your time & provides tools to help you be more productive.
Appogee Leave - PARIM Workforce Management Software
Clockify - Simple and free time tracker. Perfect for small and mid-sized businesses as well as freelancers. Unlimited projects and users, unlimited productivity. Get all the premium functionalities, completely free.
CWS TimeOut - CWS TimeOut is an online leave tracking software or absence management solution that can also be installed on the server.