# How to Use the DATEDIF Function in Excel: Expert Tips!

The **DATEDIF function** in Excel is a powerful yet lesser-known formula that allows users to calculate the difference between two dates. Whether you are managing projects, tracking time between events, or calculating ages, this function comes in handy for determining the **time difference** in various units like **days, months, or years**.

In this article, we will guide you on how to use the **DATEDIF function** effectively, including its syntax, examples, and common use cases.

## What is the DATEDIF Function?

The **DATEDIF function** is an Excel formula used to calculate the difference between two dates. You can return results in different units of time, such as days, months, or years. It’s especially useful in scenarios like **calculating age** or determining how much time has passed between two events.

### Syntax of DATEDIF Function

`=DATEDIF(start_date, end_date, unit)`

**start_date**: The starting date.**end_date**: The ending date. It must be after the start date.**unit**: This specifies the time unit (like “D” for days, “M” for months, etc.) in which you want the difference.

## Units for DATEDIF Function

The **unit** parameter plays a critical role as it determines how the **DATEDIF function** will return the result. Below are the common units and their meanings:

Unit | Description |
---|---|

“Y” | Difference in years |

“M” | Difference in months |

“D” | Difference in days |

“MD” | Difference in days, ignoring months and years |

“YM” | Difference in months, ignoring years |

“YD” | Difference in days, ignoring years |

## How to Use DATEDIF in Excel

Let’s break down how to calculate the **difference between two dates** using the **DATEDIF** function.

### Step 1: Input the Dates

Enter the start and end dates in two different cells. For example:

**A1**: 01/01/2020**B1**: 12/31/2023

### Step 2: Apply the DATEDIF Formula

Now, in another cell, enter the following formula:

`=DATEDIF(A1, B1, "Y")`

This formula calculates the number of full **years** between the two dates. The result will be **3**, indicating that 3 full years have passed between 01/01/2020 and 12/31/2023.

### Step 3: Calculate in Other Units

- To calculate the difference in
**months**, change the**unit**to`"M"`

:

` =DATEDIF(A1, B1, "M")`

The result will be **47**, showing that 47 months have passed.

- To calculate the total difference in
**days**, use the`"D"`

unit:

` =DATEDIF(A1, B1, "D")`

The result will be **1,460** days.

## Practical Examples of Using DATEDIF in Excel

The **DATEDIF function** is versatile and can be used in several real-life scenarios. Let’s explore some examples.

### Example 1: Calculating Age

Suppose you want to calculate someone’s age based on their **birthdate**. You can use the DATEDIF function with the **“Y”** unit to find the difference in years.

**A2**: 07/15/1990 (Birthdate)**B2**: TODAY() (Current Date)

The formula would be:

`=DATEDIF(A2, TODAY(), "Y")`

This will return the person’s **age in years**.

### Example 2: Tracking Project Duration

If you are managing a project and need to calculate the total duration in **months**, DATEDIF can help.

**A3**: 03/01/2021 (Project Start Date)**B3**: 06/30/2022 (Project End Date)

To calculate the project duration in months:

`=DATEDIF(A3, B3, "M")`

The result will be **15 months**.

### Example 3: Ignoring Years or Months

In some cases, you may want to calculate the **difference in days** but ignore the years or months. For this, you can use the **“MD”** or **“YM”** units.

**“MD”**ignores months and years, calculating the days only.**“YM”**ignores years, calculating only the months.

For example:

`=DATEDIF(A1, B1, "YM")`

This formula will calculate the difference in **months** between the dates, ignoring years.

## Combining DATEDIF with Other Excel Functions

You can also combine the **DATEDIF function** with other Excel functions like **IF** to create more dynamic formulas.

### Example: Age Calculation with Conditional Formatting

You can calculate age and apply conditional formatting to highlight certain ages. For example:

`=IF(DATEDIF(A2, TODAY(), "Y")>=18, "Adult", "Minor")`

This formula will return “Adult” if the person is **18 years or older**, and “Minor” if they are younger.

## Limitations of the DATEDIF Function

While **DATEDIF** is useful, it comes with some limitations:

**Start date must be earlier**than the end date. If not, the formula will return an error.**Incorrect results for negative dates**: If dates are incorrectly entered, you may get erroneous results.**Not officially documented**: The**DATEDIF**function is not listed in the official Excel function list, so you may not find direct support in Excel’s help guide.

## Error Handling with DATEDIF

When working with **DATEDIF**, there are some common errors you may encounter:

**#NUM! error**: This occurs when the**start date**is greater than the**end date**. Ensure the correct date order is used.**#VALUE! error**: This happens if any date format is incorrect or if a non-date value is used.

## How to Avoid Errors in DATEDIF

- Always ensure that the
**start date**is earlier than the**end date**. - Use proper
**date formats**in your cells. - Combine the
**DATEDIF function**with error-handling formulas like**IFERROR**to manage potential issues. For example:

` =IFERROR(DATEDIF(A1, B1, "D"), "Error in date calculation")`

This will prevent your formula from showing errors in the result.

## Using DATEDIF to Calculate Time Differences in Different Scenarios

The **DATEDIF function** can handle a variety of **date differences**, making it useful in many professional contexts:

**Human Resources**: Calculate employee tenure by finding the difference between**hire date**and**current date**.**Finance**: Track investment durations by calculating the time between the**investment start date**and**maturity date**.**Project Management**: Measure project timelines to keep track of milestones and deadlines by calculating the time difference between**start date**and**target completion date**.

## Visualizing the Date Difference with a Table

To make your calculations more accessible, you can visualize the date differences using tables. Here’s a table summarizing the **difference between two dates** using various **DATEDIF units**:

Start Date | End Date | Unit | Formula | Result |
---|---|---|---|---|

01/01/2020 | 12/31/2023 | “Y” | `=DATEDIF(A1, B1, "Y")` | 3 years |

01/01/2020 | 12/31/2023 | “M” | `=DATEDIF(A1, B1, "M")` | 47 months |

01/01/2020 | 12/31/2023 | “D” | `=DATEDIF(A1, B1, "D")` | 1,460 days |

## Final Thoughts

The **DATEDIF function** is a powerful tool that simplifies the process of calculating the **difference between two dates** in various units like **years**, **months**, and **days**. While it may not be as well known as other Excel functions, mastering **DATEDIF** can save you a lot of time and effort in tasks related to date calculation.

Remember to use proper **date formats**, handle errors with functions like **IFERROR**, and combine **DATEDIF** with other Excel formulas for more dynamic calculations.

## Frequently Asked Questions

### What is the DATEDIF function in Excel used for?

The DATEDIF function in Excel is used to calculate the difference between two dates in terms of years, months, or days. It’s commonly used for tracking time differences, calculating age, or managing project durations.

### What are the valid units for the DATEDIF function?

The valid units for the DATEDIF function include “Y” for years, “M” for months, “D” for days, “MD” for the difference in days ignoring months and years, “YM” for the difference in months ignoring years, and “YD” for the difference in days ignoring years.

### How do I calculate the difference between two dates in years?

To calculate the difference between two dates in years, use the formula: =DATEDIF(start_date, end_date, “Y”). This will return the number of full years between the two dates.

### Can I calculate the difference between two dates in days without considering months?

Yes, you can calculate the difference in days without considering months or years by using the formula: =DATEDIF(start_date, end_date, “MD”). This will return the number of days between the two dates, ignoring the months and years.

### What does the #NUM! error mean in the DATEDIF function?

The #NUM! error occurs in the DATEDIF function if the start date is later than the end date. Ensure the start date is earlier than the end date to avoid this error.

### How can I calculate the difference between two dates in months and days?

To calculate the difference between two dates in months, use the formula: =DATEDIF(start_date, end_date, “M”). For the difference in days without considering months or years, use “MD” as the unit. You can combine these formulas to calculate the difference in months and days.

Vaishvi Desai is the founder of Excelsamurai and a passionate Excel enthusiast with years of experience in data analysis and spreadsheet management. With a mission to help others harness the power of Excel, Vaishvi shares her expertise through concise, easy-to-follow tutorials on shortcuts, formulas, Pivot Tables, and VBA.