Excel® 2010 Workbook for Dummies®

Chapter 8. Creating Date and Time Formulas

In This Chapter

• Building date and time formulas

• Using the Date functions

• Using the Time functions

Formulas that perform calculations between elapsed dates and times are quite common in spreadsheets. The exercises in this chapter give you a chance to build formulas that calculate the difference between starting and ending dates and times as well as to use Excel Date and Time functions to perform a variety of tasks, including returning the current date and time in a spreadsheet, converting text entries to valid date and time numbers, and more.

Constructing Date and Time Formulas

You already have some experience entering dates and times in a worksheet and then changing how they appear by assigning different date and time number formats. Remember that all you need to do when you enter a date or time number in a worksheet is to emulate one of these date or time number formats when making the entry.

The only thing the least little bit baffling about date and time entries in a worksheet is the actual way that Excel stores the date and time numbers into a cell when you make an entry following one of the standard number formats. Behind the scenes (that is, the date or time number formats) lies a serial number. In the case of dates, this serial number represents the number of days that have elapsed between the date you enter and the beginning of the twentieth century (making January 1, 1900 serial date number 1). In the case of time, the serial number is ...