Calendar Overlay Using Custom List in Office 365

Calendars Overlay is the feature in SharePoint that allows users to view the data of various types of lists, for example Custom List, task lists and Microsoft Exchange calendars. The purpose of the Calendar Overlay feature in SharePoint 2010 is to aggregate multiple calendars into one master calendar.

The following is a step-by-step procedure to create a Calendar overlay using a Custom List in Office 365.

Step 1: Create a Custom List named ClientProject

Create a Custom List

Step 2: Add records in the List as below:
 
Add records in the List

Step 3: Go the List ribbon and click the Create View button.
 
Create View button

Step 4: In the Create View page, click the Calendar View link.
 
Calendar View link

Step 5: Type in a Name for the view, such as ProjectCalendarView.

Step 6: We have two relevant date columns in this List, so we'll choose StartDate and EndDate in the Begin and End fields respectively in the Time Interval section. Use the Title as the item heading in the Month, Week, and Day views.
 
StartDate and EndDate

Step 7: Add any other necessary settings as per your requirements and click OK.

Step 8: The resulting Calendar view looks such as below:
 
Calendar view

Step 9: Add a calendar in the Site

Step 10: On the New Calendar page, type in a name for the Calendar MyCalendar.
 
New Calendar page

Step 10: Choose a color for this Calendar View

Step 11: Next, add the URL of the site (or subsite) for the Calendar. By default, it fills in the URL of the subsite you are working with. In this case, that is correct. If you were trying to bring in a Calendar from another subsite, you need to type or paste in that URL. With the correct URL in place, click the Resolve button.

Step 12: When the URL resolves, the List field just below will be populated

Step 13: From this drop-down, you need to select the Calendar you are working on.

Step 14: Next choose the view you have created.
 
choose the view

Step 15: Click OK.

Step 16: You can repeat the same for all the calendars and customize their overlay.
 
calendars overlay

Step 17: Create another view in the list and repeat all the preceding procedure to add another calendar to the existing one by clicking Calendar Overlays.
 
Create another view

Step 18: In my case, I created another view for the Completed projects as below:
 
Completed

Conclusion

In this article I have explained how to create a calendar view and keep multiple views on a single calendar.