The truth is yes. The date of birth calculator also includes the end date in the results provided to the user. It is helpful for those who want to know how many days a particular event has lasted. For example, if you have to work from day 1 to day 4 in a week, your final day result will be 4. Many believe the last day (the end date) is not counted as an additional date. Therefore, you should uncheck this item when calculating the exact age of an event or phenomenon.