Your first use of formula fields tracks the age of a Position posting with a simple calculation.
Return to the main page for the Position object and click New in the Custom Fields & Relationships section.
Select Formula as the data type and click Next to bring up the page shown below. You define the basic attributes of the formula field on this page.
Figure 56. Defining a formula
Enter Days Since Posting in the Field Label field and select Number as the return type for the formula since this formula returns the number of days since the position was posted. Set the number of Decimal ...