From time to time, I have to lead projects that involve various people. A trick I use to avoid problems is to have all the holidays of my colleagues on my calendar so that I know when I can do what with who.

For example, this helps me know that Thomas won't be able to give me feedback but that Bob can. And it also makes it possible for me to give deadlines to the team that fit with their holidays and that aren't in the middle of them.

In some companies, this is something you don't have to do manually as everyone has to share his days off and holidays in the same system that is visible to everyone. That's even better. Still, there is value to doing it manually, as you can add the holidays of partners outside your organisation to your calendar for better planning.