Each time you visit a To Do List worksheet it is automatically refreshed for the current date and the items in the list. If you are visiting a To Do List for the first time on a day you may notice that the items are refreshed for formatting and that items that were clear format are now either indicated with a warning "Blue" format for items approaching their due date or a warning "Yellow" format for items that are overdue.
As you update a list for new Due Dates or changes in the Estimated Effort you will notice that the list is automatically refreshed each time, this ensures that you are aware of any warnings that might result from the changes you have made to those lists.
Note: A shortcut to Refresh the current active list use Ctrl+R to refresh.
To Refresh the currently active To Do List, select 'Refresh' in the My Item section of the ribbon
The image below shows the Refresh for an active To Do List.