Is it possible to create your own holiday entries?

Yes, it is! Open the vacation calendar as administrator. You can create and edit holidays in the menu item “holiday settings” individually for your account .
Here you have two different holiday categories:

• Individually created holidays
• system holidays

System holidays are holidays which are provided and calculated annually by timenote itself. You can deactivate single system holidays (edit and deactivate holiday).

Individual holidays are for open expansion of the system holidays.
Note: A holiday which repeats itself annually on a fixed date (e.g. New Year’s Eve) can be tagged as such via the setting “repeating” for future years. It doesn’t have to be set manually every year.