The Excel TODAY function returns the current date, updated continuously when a worksheet is changed or opened. The TODAY function takes no arguments. You can format the value returned by TODAY using any standard date format. If you need current date and time, use the NOW function.
TODAY takes no parameters, but required that you use empty parentheses ().
The value returned by TODAY will continually update each time the worksheet is recalculated (for example, each time a cell value is entered or changed). Use F9 to force the worksheet to recalculate and update the value.