Calendar overlays allow you to create a combined view of your Calendars and/or To Do Lists by layering more Calendars or To Do Lists on top. If you assign dates to your Tasks on your lists you can create an overlay to use on your Calendars. This way you can view all of your Tasks and Events at once to make sure you never miss a date for a Task.
Using your To Do List as an overlay
The Tasks that have been assigned any dates in your To Do Lists (start dates and/or due dates) will appear chronologically on your Calendar alongside any Events that you have to create in your Calendar. Tasks without a start or due date will appear on the current date. Tasks without a start date or due date that have been finished will appear on the date they were finished.
There will be a checkbox next to your Tasks just like in your To Do List. If you are finished with a Task you can click the checkbox next to the task and the Task text will have a strike through it.
When you click on the checkbox next to the Task in your Calendar overlay, the change will instantly be reflected in the To Do List the Task is in. The Task in the To Do List will also have a checkmark next to it and a strike through the text.
After you click the checkbox next to the Task in your Calendar and if you navigate away from your Calendar, the Task will be removed from your Calendar. However, the Task will no be removed from your To Do List. It will stay as a finished Task on your list.
If you click directly on the Task in your Calendar a pop-up dialog will show up with your full To Do List in it. You can then easily edit Tasks directly from your calendar. The To Do List opening in a new dialog saves you the time of navigating back and forth between your applications.
Learn more about removing To Do Lists as a Calendar overlay.