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Add days to date

Excel uniquely stores dates as serial numbers, making it easy to perform calculations with dates.  Adding or subtracting days can be done by using one of the basic arithmetic operations, addition. This tutorial will assist all levels of Excel users in adding days to date.  

Figure 1.  Final result: Add days to date

Setting up our Data

Our table contains three columns: Date (column B), Days (column C) and Result (column D).  We want to add or subtract the number of days in column C from the start date in column B by using a simple mathematical operation, addition.  The results will be recorded in column D.

Figure 2.  Sample data to add days to date

Add days to date

Excel has a unique way of storing dates as serial numbers where the value “1” corresponds to the date “January 1, 1900”.  We want to add days to a start date by simply using addition. We can do this by following these steps:

Step 1.  Select cell D3

Step 2.  Enter the formula: =B3+C3  

Step 3.  Press ENTER

Step 4:  Copy the formula in cell D3 to cells D4:D9 by clicking the “+” icon at the bottom-right corner of cell D3 and dragging it down

Figure 3.  Entering the formula to add days to date

As long as a date is valid, we can directly add or subtract days to obtain results.  A positive value for days refers to a future date while a negative value pertains to a past date.  Excel is able to perform calculations involving dates because each date is stored as a serial number.

For our first example, 1/27/2019 has the serial number 43492.  We add 9 days and the result is the date “2/5/2019”, whose serial number is 43501.  Our formula looks like this:

43492 + 9  = 43501

When formatted as a date, the serial number 43501 is displayed as the date “2/5/2019”.  

For the next example, we subtract 9 days to the start date.  As a result, the date in D4 is “1/18/2019”.  

See below filled-up table that shows the results when the number of days in column C is added to the start date in column B, by using simple addition.  

Figure 4.  Output: Add days to date

Most of the time, the problem you will need to solve will be more complex than a simple application of a formula or function. If you want to save hours of research and frustration, try our live Excelchat service! Our Excel Experts are available 24/7 to answer any Excel question you may have. We guarantee a connection within 30 seconds and a customized solution within 20 minutes.

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Another blog reader asked this question today on Excelchat:
Here are some problems that our users have asked and received explanations on

I need a formula which will read "IN", in cell F3 and add 65 days to date from cell A3, or read "OW" from cell F3 and add 35 days to date from cell A3
Solved by X. A. in 16 mins
I need AE3 to look at F3 then add the days in AD3, then add the days between M3 and N3 then add the days between O3 and P3, I also need the formula to then look at F3 + AD3 and see if there are any weekends between the date and add these onto the final date.
Solved by F. D. in 19 mins
In this sheet, there are three types of requests. Re-Review, Removal, and Override. Re-Review will take the Received date and then add 30 days to get the new due date result. Removal will take the Received date and then add 7 days to get the new due date result Override will take the Received date and then add 1 days to get the new due date result. I can't figure out how to make an if statement that will have these three conditions
Solved by K. L. in 28 mins

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