Excel 2010 Bible

249

CHAPTER

Working with Dates

and Times

IN THIS CHAPTER

An overview of using dates and

times in Excel

Excel date-related functions

Excel time-related functions

M

any worksheets contain dates and times in cells. For example, you
might track information by date, or create a schedule based on
time. Beginners often find that working with dates and times in
Excel can be frustrating. To work with dates and times, you need a good
understanding of how Excel handles time-based information. This chapter
provides the information you need to create powerful formulas that manipu-
late dates and times.

Note
The dates in this chapter correspond to the U.S. English language date format:
month/day/year. For example, the date 3/1/1952 refers to March 1, 1952, not
January 3, 1952. I realize that this setup may seem illogical, but that’s the way
Americans have been trained. I trust that the non-American readers of this
book can make the adjustment. n

How Excel Handles Dates and Times ................................................................................

This section presents a quick overview of how Excel deals with dates and
times. It includes coverage of the Excel program’s date and time serial num-
ber system, and it offers tips for entering and formatting dates and times.

Understanding date serial numbers .........................................................................

To Excel, a date is simply a number. More precisely, a date is a serial number
that represents the number of days since the fictitious date of January 0, 1900.