Managers often get a lot of meeting invitations and I am no exception. And when it comes to meetings with many busy participants they sometimes tend to be scheduled very early in the morning, very late in the evening, during lunch breaks or on Fridays. So if you don’t enforce any rules on your calendar, it might soon be full of meetings on all days at all times. One countermeasure is to make sure you only attend meetings that have a proper agenda which shows you why you need to be there, but besides that you also need something else: Time without meetings. Because in order to be a good manager, you have to follow-up on your action items from those meetings and attend your other responsibilities too. And some of those tasks will require some contiguous time without any interruptions. That is why you have to block focus time in your calendar and defend this time against everything that is not absolutely crucial (and that means you decide if something is crucial).
You can decide yourself when the best time for these blockers is, but I myself use my Wednesday afternoon and the entire Friday both of which I work from home to be able to shut down any external interruptions if needed. The Wednesday afternoon is mainly to follow-up on open ToDos from mails or meetings whereas the Friday also includes several other responsibilities that I want to make sure get regular focus. Those include a review of all of my open tasks (across Outlook, Obsidian, Confluence and Jira), project risk analysis, vacation requests of team members, time-tracking related requests, budget controlling and self-improvement. This way, I can start into my weekend with a good feeling that I have everything settled for the week.