# DATEDIF

Calculates the number of days, months, or years between two dates.

### Sample Usage

`DATEDIF(DATE(1969, 7, 16), DATE(1969, 7, 24), "D")`

`DATEDIF(A1, A2, "YM")`

`DATEDIF("7/16/1969", "7/24/1969", "Y")`

### Syntax

`DATEDIF(start_date, end_date, unit)`

• `start_date` - The start date to consider in the calculation. Must be a reference to a cell containing a `DATE`, a function returning a `DATE` type, or a number.

• `end_date` - The end date to consider in the calculation. Must be a reference to a cell containing a `DATE`, a function returning a `DATE` type, or a number.

• `unit` - A text abbreviation for unit of time. For example,`"M" ` for month. Accepted values are `"Y"`,`"M"`,`"D" `,`"MD"`,`"YM"`,`"YD"`.

• `"Y"`: the number of whole years between ` start_date` and `end_date`.

• `"M"`: the number of whole months between ` start_date` and `end_date`.

• `"D"`: the number of days between `start_date ` and `end_date`.

• `"MD"`: the number of days between `start_date ` and `end_date` after subtracting whole months.

• `"YM"`: the number of whole months between ` start_date` and `end_date` after subtracting whole years.

• `"YD"`: the number of days between `start_date ` and `end_date`, assuming `start_date` and `end_date` were no more than one year apart.

### Notes

• Months and years are only counted if they are equal to or go past the "day." For example, the function returns "4 months" between the dates 9/30/15 and 2/28/16 (even though the 28th is the last day of the month).

• If `DATEDIF` produces a result in an unexpected format, ensure that no pre-existing format has been applied to the cell. For example, if `DATEDIF(DATE(1969,7,16),DATE(1969,7,24),"D")` returns `1/4/1900`, the `Date` format has been applied to the cell. Change the format of the cell to `Number` in order to view the expected result of `8`.

• Use `unit` `"MD"` to answer questions such as, "After subtracting whole years and whole months from my age, how many days old am I?"

• Use `unit` `"YM"` to answer questions such as, "After subtracting whole years from my age, how many whole months old am I?"

• Use `unit` `"YD"` to answer questions such as, "How many days has it been since my last birthday, given my birthdate and today's date?"

`DATE`: Converts a year, month, and day into a date.

`DATEVALUE`: Converts a provided date string in a known format to a date value.

## Examples

Note: Each example is in its own tab.

### Number of days

In this example, `DATEDIF` returns the number of days in the Apollo 11 mission.

### Months

In this example, `DATEDIF` returns the number of months in one year.