User is noticing that terminated employees are appearing in Timers. Why?
This is caused by the 'Auto-fill timer with the last projects/activities' setting in User Preferences > Time. If you use this auto-fill setting, CORE takes projects and activities of your chosen date into account. This can include terminated employees as well, which is why they appear in your timers. This will change over time as you work on different projects and activities. Alternatively, you can turn off that setting for some time.