## Date Formulas

Dates are one of the common types of data stored in Excel worksheets. If you need to work with dates in some manner, you need to understand how to pull those dates apart in formulas. Here are ideas, tricks, and pointers on how you can better manipulate the dates you face working with.

### Tips, Tricks, and Answers

The following articles are available for the 'Date Formulas' topic. Click the
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**Adding Ordinal Notation to Dates**

Want to add an ordinal suffix to a number, as in 2nd, 3rd, or 4th? Excel doesn't provide a way to do it automatically, but the ideas presented here can be helpful in devising a way to get the desired notation.

**Ages in Years and Months**

Calculating an age is a common task when working with dates. If you want to figure out the number of years and months between two dates, you'll appreciate the discussion in this tip.

**Automatically Advancing by a Month**

Excel allows you to perform quite a few operations using dates in your worksheet. Sometimes, however, the answer may not be immediately obvious. For instance, if you want to perform an operation that always advances the date to the beginning of the next month once half the month has passed.

**Backwards Date Parsing**

Enter information into a worksheet, and you come to anticipate (and count on) how Excel will interpret that information and store it in the worksheet. If you suddenly find that Excel isn't parsing your date entries correctly, there are two possibilities you should check out right away.

**Calculating a Date Five Days before the First Business Day**

Excel allows you to perform all sorts of calculations using dates. A good example of this is using a formula to figure out a date that is five days before the first business day of any given month. This tip shows how easy Excel makes such a calculation.

**Calculating a Group Retirement Date**

Calculating a retirement date can be as simple as doing some date math to see when a person reaches a certain age. Calculating a date after the retirement age is reached is a bit more complex.

**Calculating a Sum for a Range of Dates**

If you use Excel to track information based on dates, you may wonder how to get a sum for only certain dates that you tracked. Fortunately, Excel provides a couple of summing functions that can make quick work of summing values based on the criteria you specify.

**Calculating an Age On a Given Date**

Start putting dates in a worksheet (especially birthdates), and sooner or later you will need to calculate an age based on those dates. There are a few ways you can accomplish this in Excel, as described in this tip.

**Calculating Averages by Date**

When you have a huge amount of daily data to analyze, you may want to calculate an average of values for any given date in the data. This may seem daunting, but can be done relatively easily using the formulas described in this tip.

**Calculating Business Days**

There are calendar days and then there are business days. Excel provides two functions (NETWORKDAYS and NETWORKDAYS.INTL) that are helpful to figure out how many business days there are between two dates.

**Calculating Differences in Months using Non-Standard Date Values**

Dates can be entered into a worksheet in any number of unique or novel ways. Working with those dates can be a challenge, though, as demonstrated in this tip.

**Calculating Fractions of Years**

When working with dates and the relationship between dates, Excel provides a variety of worksheet functions that may prove helpful. One such function is YEARFRAC, which allows you to calculate what fraction of a year is represented by the number of days between two dates.

**Calculating Future Workdays**

Need to calculate the date that is a certain number of workdays in the future? You can do so using a couple of different worksheet functions, as described in this tip.

**Calculating Months for Billing Purposes**

Different businesses have different ways to calculate elapsed time for billing purposes. Figuring out a formula that reflects your company's calculation method can be challenging.

**Calculating Months of Tenure**

Need to know the number of months between two dates? It's easy to figure out if you use the DATEDIF function.

**Calculating the First Business Day of the Month**

Want to know which day of the month is the first business day? The easiest way to determine the date is to use the WORKDAY function, as described in this tip.

**Calculating the Last Day in a Week Number**

Given a particular week number for a year, you may want to figure out the date of the last day in that week. There is no intrinsic function to derive the desired date, but you can use one of the formulas presented in this tip.

**Calculating Week-Ending Dates**

When working with dates, you may need to figure out all the dates on which weeks end in a given year. There are several formulaic ways to accomplish this task, as described in this tip.

**Calculating Weekend Dates**

Do you look forward to the weekend? Well, you can use Excel to let you know when the next weekend begins. Here's how you can create a formula that will tell you the next Saturday after a given date.

**Converting an Unsupported Date Format**

Excel makes it easy to import information created in other programs. Converting the imported data into something you can use can present a challenge. Here's how to make a change from an unsupported date format to one that Excel can work with.

**Converting Coded Dates into Real Dates**

Sometimes the format in which you receive data is not the same format that would be optimal for Excel. For instance, you might receive some data that shows dates in a strange format, such as '04C13'. This tip explains how you can convert such strange formats into something you can use.

**Converting Dates to Text**

Need to use a date as part of a larger string of text? Here are some handy ways to go about the process.

**Converting European Dates to US Dates**

Those in Europe use a date format that is different than those in the US; this is not news. But what if you need to convert those European dates to US dates? There are several ways you can make the conversion, depending on your needs.

**Converting Mainframe Date Formats**

Different industries and different computer systems specify dates in all sorts of strange ways. If you need to convert a date from an off-beat format into one that Excel can understand, you'll like the technique used in this tip.

**Converting Time Notation to Decimal Notation**

Want to convert an elapsed time, such as 8:37, to a decimal time, such as 8.62? If you know how Excel stores times internally, coming up with the conversion formula is a snap.

**Converting UNIX Date/Time Stamps**

If you import information generated on a UNIX system, you may need to figure out how to change the date/time stamps to something that Excel can recognize and work with. The conversion is easy, once you understand the way in which the date/time stamps are figured.

**Copying Dates a Year Into the Future**

Need to copy a range of dates and update them to a different year? Here are a number of ways to accomplish this task with a minimum of fuss.

**Counting Dates in a Range**

Excel makes working with a list of dates relatively easy. If you have a list of dates, you may need to know how many of those dates fall within a certain range. Here's how to get the count you need.

**Date for Next Wednesday**

When working with dates, it is often helpful to be able to calculate some date in the future based on a starting date. Figuring out future days of the week based on some starting date can be trickier still. Here's a wide range of formulas that can help you figure out the date of the next Wednesday, starting from any date.

**Days Left in the Year**

Sometimes it is handy to know how many days are left in the current year. This tip provides a quick formula that indicates the number remaining.

**Deciphering a Coded Date**

It is no secret that Excel allows you to work with dates in your worksheets. Getting your information into a format that is recognized by Excel as a date can be a challenge, at times. Here is an examination of how to make sense out of a coded date so it can be worked with in Excel.

**Determining Business Quarters from Dates**

Many businesses organize information according to calendar quarters, especially when it comes to fiscal information. Given a particular date, you may wonder how you can determine the quarter of the year in which that date falls. There are a number of ways you can devise formulas for such an answer.

**Determining If a Date is between Other Dates**

Need to figure out if one date is between two other dates? There are a wide variety of formulaic approaches you could use to determine the answer. Here are two short and elegant approaches.

**Determining If a Year is a Leap Year**

Need to figure out if a given year is a leap year? It's not as easy as you think! This tip provides a plethora of ways that you can accurately make the determination.

**Determining Month Names for a Range of Dates**

Given a starting date and an ending date, you may want to generate the names of all the months between those two dates. This tip examines several ways you can determine the information.

**Displaying a Number as Years and Months**

How do you display a number of years, such as 3.67 years, as a number of years and months? It's simple to do with a formula, as discussed in this tip.

**Elapsed Days as Years, Months and Days**

Need to know how many days there are between two dates? It's easy to figure out—unless you need the figure in years, months, and days. Here's why.

**End-of-Month Calculations**

Don't want to use the EOMONTH function to figure out the end of a given month? Here are some other ideas for discovering the date you need.

**Entering Dates without Separators**

When doing data entry into a worksheet, you might want to enter dates without the need to type the separators that are normally part of those dates. Here's a discussion on how this can be done in Excel, along with the benefits and drawbacks of using such an approach.

**Every Second Tuesday**

Need a way to enter dates from every second Tuesday (or some other regular interval)? Excel makes it easy, providing several different methods of entering the information.

**Finding the Dates for Minimums and Maximums**

If you use Excel to maintain a collection of data, you may need to find information in one column based on information in an adjacent column. This tip shows a couple of approaches to getting the information you need.

**Finding the Previous Work Day**

Simple math will tell you what the previous day is (just subtract 1 from today's date). What if you want to know the date of the previous workday, however? That can be almost as easy as simple math.

**Forcing Dates Forward**

Want to push a date to some pre-defined day of the month? Here are some ways to force the issue.

**Including Weeks in Elapsed Time**

When showing how much time has elapsed between two dates, it is sometimes helpful to express the result in terms of elapsed years, months, weeks, and days. This tip shows how to arrive at such an answer using a relatively simple formula.

**Incrementing Months in Dates**

Excel can easily store dates. If you want to increment a date by one month, there are a number of ways you can accomplish the task. Here are some ideas.

**Inserting Tomorrow's Date**

You can use a couple of different worksheet functions to enter today's date in a cell. What if you want to calculate tomorrow's date or some other date a certain number of days in the future? It's easier than you might think to figure out that future date.

**ISO Week Numbers in Excel**

Work in an industry that uses ISO standards when it comes to working with dates? You'll love the formula in this tip which explains how to determine the week number, of the year, for a given date.

**Leap Years and Fiscal Periods**

Need to figure out when a fiscal year ends when that period does not correspond to the calendar year? Here are some ways that you can do the calculation and make sure you take leap years into account.

**Monthly Close-Out Dates**

If your company closes out its accounting months at the end of each calendar quarter, figuring out the proper closing dates is a snap. It can be more challenging to figure out other closing dates, but it can be done by applying the techniques in this tip.

**Parsing Non-Standard Date Formats**

When you load data into Excel that was created in other programs, the formatting used for some types of data (such as dates) may not be understood by Excel. Here's how to convert the data to a format that can be used by the program as you expect.

**Pulling All Fridays**

It can be handy to know when specific weekdays occur within a range of dates. Figuring out this information, using formulas, can be tricky. Here's how to get just the dates you need.

**Pushing Dates Into Last Month**

Excel is great when it comes to working with dates and times. You can even do math on dates. One such easy manipulation is to determine the last day of the month prior to a given date. This tip shows how.

**Returning Nothing If Two Values are Empty**

Excel includes a large number of functions that can be used in evaluating the data in a worksheet. In this tip you learn various ways you can utilize those functions to determine if two input cells are empty.

**Rounding to the Nearest Quarter Hour**

When entering times in a worksheet, you may have a need to round whatever you enter to the nearest 15-minute increment. There are a variety of ways you can approach this problem, as you learn in this tip.

**Sorting Dates and Times**

One of the strong features of Excel is its ability to sort information in a worksheet. When it doesn't sort information as you expect, however, it can be confusing. Here's a look at why your dates and times might not sort the way you want them to.

**Specifying Different Weekends with NETWORKDAYS**

The NETWORKDAYS worksheet function can be used to easily determine the number of work days (Monday through Friday) within a range of dates. If your workweek consists of different days, however, the NETWORKDAYS function may not be the best place to start.

**The Last Business Day**

Many businesses need to know when the last business day of the month occurs. This tip discusses several ways you can calculate this date in Excel.

**Tombstone Date Math**

Doing math with dates is easy in Excel. Doing math with old dates—such as those you routinely encounter in genealogy—is a different story. Here's how you can figure out birth or death dates given one or the other and a precise age.

**Unique Date Displays**

Need to print an elapsed date in a strange format? It's easier to do than may appear at first glance. Here's a discussion on how to get your results in just the format you want.

**Unique Military Date Format**

Some industries (such as the military) have special formatting that they use to represent dates. Here is one such format and how you can create the format in Excel.

**Using Early Dates**

Excel is brilliant at handling dates—as long as they aren't dates earlier than the base date used by the program. If you need to use earlier dates, then you'll want to be aware of the information in this tip.

**Weekdays in a Month**

Want to find out how many of a particular weekday occur within a given month? Here's how you can find the desired information.