Outlook provides only available times wich are within your "working hours" as configured in your outlook account.
To disable this option, and allow full sync with vCita please follow the steps below:
1. Open Outlook
2. Click on Send\Receive tab in ribbon
3. Click on Work Offline.
Note: You have to click on the same Word Offline tab to enable and disable it.
When Work Offline is highlighted, it means that it is enabled. Click on the same work Offline, when it is not highlighted then it is disabled.