Fixing SharePoint 2010 Calendar Overlays After a Move with PowerShell

If you ever move a calendar from one place to another, either as part of a site move or a list move, you will be greeted by the fact that your calendar overlays no longer work because the URLs to the overlaying calendars are hardcoded into the list view. I am trying to set up an automated restore from production to development, so having lots of broken calendars isn’t great. Fortunately, all you have to do is run a few lines of PowerShell to fix this.

How to Configure a Filtered Calendar Overlay in SharePoint 2010

Calendar Overlays was definitely a welcome new feature when SharePoint 2010 was released. They provide decent basic functionality for being to have a nice view of multiple calendars at once (up to 10 calendars). Suppose you are in a situation where you want to do some calendar overlays, but you only want to show a filtered set of calendar entries on the calendar overlay view? This turns out to be much easier than it might sound. Now you could write a simple workflow that runs on the child list and copies the list item on the child calendar to the parent calendar, but that’s not really an overlay is it?

As I said, this is actually extremely easy to configure. It feels like it should be illegal to be this easy, so enjoy the moment! So what do we need to do? Here are the overview steps:

• Create at least 2 calendars (one child, and one parent used to display the overlay)
• Create items on the child calendar
• Create a filtered Calendar View on the child calendar (e.g. only show items where category=X)
• On the parent calendar, configure the overlay, and be sure to choose the new filtered view
• Sit back, have a drink and bask in the awe of your coworkers and boss as they bow before you in the view of this incredible display of SharePoint awesomeness