There are a lot of (complex) solutions out there to create a master calendar in SharePoint. Sometimes it is really simple. Take a look at this example:
We have a master calendar where we store the main appointments for all teams. This calendar has approval on it. When an item is approved we want a copy of it in a few calendar lists on different sites in the same site collection.
- Useful SharePoint Designer Custom Workflow Activities: can be downloaded from codeplex. Install it on you servers.
Create a calendar on you main site, enable approval and ensure yourself that the members of the approval group have contribution rights to each calendar you want to update because the workflow will start on approval and will run under the context of the approver.
Start SharePoint Designer and create a new workflow on the calender list. The startup options for the workflow are on create.
In the workflow we wait until the item is approved. After approval we copy the item to one or more lists using the new activity: “Copy list item extended”.
Repeat the last step for each list you want to update.