If you would like to add some team-specific Holidays to several staff and have them added automatically in the People Planner, you can create a new Holiday Group for this team, and add Custom Holidays to the Holiday Group on top of the Public Holidays.
Hover your cursor over your account name on the right, click Settings
Select Public Holidays in the horizontal bar
Click New Holiday Group
Select a country and region where the team is based. Give the holiday group a name.
A list of all the public holidays for that region will appear. De-select the ones that you do not want to include.
Click Custom Holidays and add the team-specific custom holidays
Click Create
Adding People to Holiday Groups
From the Public Holidays page, click on the 3-dot menu and select Edit People
Click Add People
Search for the people you wish to add and click Add Selected
All future public and custom holidays for that holiday group will get automatically added to the people's schedules.
If these people previously belonged to another Holiday Group (perhaps the group with just Public Holidays), they will be removed from the old Group and the holidays will not duplicate.
What if the team does not share the same public holidays?
In that case, you cannot use this feature and would have to add them as Scheduled Leave in the People Planner.