Note: Outlook for Mac for Office 365 and the Outlook for Mac application released as part of the Office 2016 for Mac Preview are the same product, so this blog applies to both as long as they are updated to version 15.8 or higher.
The 15.8 update for Outlook for Mac was released on March 5, 2015, and it contains a new feature: Side-by-Side calendars. This feature allows you to view up to 3 calendars side-by-side instead of in overlay view. You can use this feature with your own calendars and shared calendars.
Before this feature was introduced (in Outlook for Mac 15.6 and lower versions), multiple calendars could be viewed at the same time in overlay view only. In the screenshot below, notice that 3 Calendars are selected in the navigation pane, and 3 different meetings appear on the calendar. These 3 meetings are located in each of the 3 calendars and are viewed in Overlay view.
Now in version 15.8 and higher with the Side-by-Side Calendar feature, you have the option of viewing multiple calendars in Side-by-Side view, as shown below.
Overlay view is still an available option, which is located on the Organize tab in the Calendar. Simply click it to enable or disable Overlay view.
You can view up to 3 calendars in Side-by-Side view at a time. When you select more than 3 calendars the view switches to Overlay view automatically. If you have more than 3 calendars selected, you will not be able to click the Overlay button to disable it. You must deselect calendars until you have 3 or fewer selected to view the calendars in Side-by-Side view again.
An option to change the view when in Side-by-Side view is to click the arrows on the calendar tabs in order to collapse the calendars so they are overlaid over the other calendar(s). You can click the left arrows on the calendar tabs to collapse them, and then the arrow on the calendar tab changes to a right arrow so you can move it to the side again. You can collapse the calendars in this manner in any combination of calendars that you prefer.
Arranging Multiple Calendars
You can arrange the calendars when they are in Side-by-Side view by selecting them in a specific order. They will appear in the order you select them from left to right. For example, if you deselect all calendars, then select Calendar 2, then select Calendar 3, and then select the primary Calendar, they will appear in that order, as shown in this screenshot:
As another example, if you have 3 calendars open in Side-by-Side view, and you would prefer have the 2 additional calendars collapsed together and your primary calendar separate on the side, follow the steps below.
Another new feature introduced in Outlook for Mac for Office 365 version 15.4 is Calendar Color. This allows you to assign a color to each calendar to make it easier to tell them apart. To choose a color, right-click the Calendar, select Color, and click the color you prefer.
Each calendar tab will display the color assigned to that calendar. Meetings that do not have a category assigned to them will appear as the color assigned to the calendar in which they are located.
Any calendar item with a category assigned will be displayed with that category color instead of the color assigned to the Calendar. Category colors override the Calendar color.
The Calendar Color feature is also very helpful when you are viewing several calendars in Overlay view, as the colors make it easier to determine which item belongs to which calendar based on the color.
Notice in the above screenshot that the Calendar 1 items appear a normal color, while the Calendar 2, 3 & 4 items appear faded. This is because "Calendar", which contains the Calendar 1 items, is the highlighted calendar in the Navigation pane on the left. This is another way to determine which items belong to the calendars.