# DATEDIF function: Description, Usage, Syntax, Examples and Explanation

## What is DATEDIF function in Excel?

DATEDIF function is one of Date and Time functions in Microsoft Excel that calculates the number of days, months, or years between two dates. Warning: Excel provides the DATEDIF function in order to support older workbooks from Lotus 1-2-3. The DATEDIF function may calculate incorrect results under certain scenarios.

## Syntax of DATEDIF function

DATEDIF(start_date,end_date,unit)

**Start_date:** A date that represents the first, or starting, date of the period. Dates may be entered as text strings within quotation marks (for example, “2001/1/30”), as serial numbers (for example, 36921, which represents January 30, 2001, if you’re using the 1900 date system), or as the results of other formulas or functions (for example, DATEVALUE(“2001/1/30”)).

**End_date: ** A date that represents the last, or ending, date of the period.

Note: If the Start_date is greater than the End_date, the result will be #NUM!.

Unit The type of information that you want returned:

Unit | Returns |

“Y” | The number of complete years in the period. |

“M” | The number of complete months in the period. |

“D” | The number of days in the period. |

“MD” | The difference between the days in start_date and end_date. The months and years of the dates are ignored. Important: We don’t recommend using the “MD” argument, as there are known limitations with it. See the known issues section below. |

“YM” | The difference between the months in start_date and end_date. The days and years of the dates are ignored |

“YD” | The difference between the days of start_date and end_date. The years of the dates are ignored. |

## DATEDIF formula explanation

- Dates are stored as sequential serial numbers so they can be used in calculations. By default, December 31, 1899 is serial number 1, and January 1, 2008 is serial number 39448 because it is 39,448 days after January 1, 1900.
- The DATEDIF function is useful in formulas where you need to calculate an age.

## Examples of DATEDIF function

Steps to follow:

1. Open a new Excel worksheet.

2. Copy data in the following table below and paste it in cell A1

Note: For formulas to show results, select them, press F2 key on your keyboard and then press Enter.

You can adjust the column widths to see all the data, if need be.

Start_date |
End_date |
Formula |
Description (Result) |

1/1/2001 | 1/1/2003 | =DATEDIF(Start_date,End_date,”Y”) | Two complete years in the period (2) |

6/1/2001 | 8/15/2002 | =DATEDIF(Start_date,End_date,”D”) | 440 days between June 1, 2001, and August 15, 2002 (440) |

6/1/2001 | 8/15/2002 | =DATEDIF(Start_date,End_date,”YD”) | 75 days between June 1 and August 15, ignoring the years of the dates (75) |