Excel 2013 contains a number of new functions that are available to work with that are available in the Function Library group of the FORMULAS tab.
Some of the new functions include the following. To view all of the functions, click each button in the Function Library.
DECIMALfunction: Available on the Math & Trig tab. This function converts the text of a number in a given base into a decimal number.
ACOTfunction: Available on the Math & Trig tab. This function returns the arccotangent of a number.
ENCODEURLfunction: Available on the More Functions tab in the Web section. This function returns a URL-encoded string.
DAYSfunction: Available on the Date & Time tab. This function shows the number of days between two dates.