Creating a solution > About choosing a field type > About date fields
 
About date fields
Use date fields to store:
dates you need to sort or search through
dates used in calculation formulas or summary fields
Notes 
The separators in date fields and the order in which the date parts appear depend on the system formats set for the file and the display format for the field. For information on changing the display format for a field (for example, July 7, 2019 or 7/7/2019), see Specifying formats for date fields.
New files and clones of existing files use the current operating system format for date formatting.
To avoid confusion when using dates in FileMaker Pro, always use four-digit years. To make sure dates are always entered with four-digit years, see Defining field validation. For information on how FileMaker Pro handles dates with two-digit years, see Entering dates with two-digit years.
FileMaker Pro stores dates as the number of days since January 1, 0001. Therefore you can calculate dates before or after a given date by subtracting or adding a number of days. For example, in a calculation field whose result is a date, the following formula calculates the date one week after the value in the DateStarted date field:
DateStarted + 7
You can also subtract one date from another to get the number of days between them. For example:
DateEnded - DateStarted
Related topics 
Defining and changing fields
Specifying formats for date fields
Working with data in date fields