# DAY Formula in Excel

In this tutorial, you will learn DAY function in excel. DAY formula in excel is useful to get the front part numeral data of a date inputted in it. The usage principles are similar to MONTH (separating the middle part/month) and YEAR (separating the last part/year) formulas.

## Why We Need to Learn About DAY Function in Excel?

In doing the processing of date data in a spreadsheet, sometimes we only need the day digit of the data to analyze, calculate, and process data as we need. So, we do a separation process of the particular digit from the whole data. If there are only a few dates to process, then probably it is still easy to do the separation process manually. However, often in the spreadsheet, we have a lot of data to process and the manual way can take a very long time to do because of this.

Besides, the date writing form in a spreadsheet can be in many variants. Thus, it will make it harder for us to do the checking process entry by entry to process the separation manually.

As an illustration of this, imagine if we have research data about the level of consumer demands in a period for a kind of product which is sold by our company and we want to analyze which period in a month when the demand level is high or low. The analysis result might be needed as the base of the company’s marketing or production activities. To do the analysis, we should separate the front part numeral data from each date in the data entries first before creating a graphic to see the demand level comparison per period.

The problem is, if we do it manually to a very high number of entries, then it will be a very long time before the graphic can be made. Besides, probably the data collection is dynamic and can be added again in terms of the amount. Thus, it will be more troublesome if there is new data and we do the separation process manually again for this.

In another case, probably we want to do a calculation process for days number only, ignoring the months and years. To do the calculation, then we need to separate those numeral data we need so the process can be easier to do. But, similar to the case before, it will be troublesome if there are many dates needed to be included in the calculation process.

For the process to be done automatically, you can use DAY formula in excel to help you. DAY function in excel can do the separation process fast, exactly as we need for the cases above, by simply giving the date input to this formula. Because of that, it is important to understand about DAY formula in excel if you often do process related to date data.

## What is DAY Formula in Excel?

DAY formula in excel is a formula with the usage objective to separate the twenty-four-hour period number part of a date. DAY function in excel is needed especially when you do calculation process related to that particular kind of numbers.

A little explanation about the input in this formula can be given as follows:

=DAY(serial_number)

Note:
serial_number = the date that you want to take the day number from

## How to Use DAY Function in Excel?

The following part will explain how to use DAY function in excel. DAY function in excel is pretty easy to use because it only needs one input in its writing.

## Using DAY Formula in Excel

1. Type equal sign ( = ) in the cell where you want to put the result in 2. Type DAY (can be with large and small letters) and open bracket sign after = 3. Type date or cell coordinate where the date which you want to process is after open bracket sign 4. Type close bracket sign 5. Press Enter
6. The process of DAY function in excel is done! ## Exercise

After you have learned how to use the DAY formula in excel above, you can practice your understanding by doing the exercise below!

### Questions

1. Fill column C with the front part numeral data of all entries in column A!
2. Fill column D with the result of the twenty-four-hour period number of column B’s cells minus its parallel in column A!
3. Fill column E with the result of the twenty-four-hour period number of today’s date minus the same number from each cell content in column A! (Use TODAY() to get today’s date!)

If you want to get month or year number from a date data of yours, then you can use MONTH (for the month) and YEAR (for the year) formulas.