Microsoft Office Tutorials and References
In Depth Information
Chapter 16: Working with Dates and Times
Working with Dates and Times
IN THIS CHAPTER
Getting an overview of dates and times in Excel
Using Excel date-related functions
Working with Excel time-related functions
Many worksheets contain dates and times in cells. For example, you might track information by
date or create a schedule based on time. Beginners often ﬁ nd 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 manipulate dates and times.
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. This setup may not seem illogical, but that’s the way
Americans have been trained. Non-American readers of this topic should make the adjustment, please.
How Excel Handles Dates and Times
This section presents a quick overview of how Excel deals with dates and times. It covers Excel’s
date and time serial number system. This section also provides some 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 ﬁ ctitious date of January 0, 1900. A serial number of 1 corresponds to
January 1, 1900; a serial number of 2 corresponds to January 2, 1900; and so on. This system makes
it possible to create formulas that perform calculations with dates. For example, you can create a
formula to calculate the number of days between two dates (just subtract one from the other).