> For the complete documentation index, see [llms.txt](https://boxlang.ortusbooks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://boxlang.ortusbooks.com/boxlang-language/reference/built-in-functions/temporal/datediff.md).
# DateDiff
Returns the numeric difference in the requested date part between two dates
## Method Signature
```
DateDiff(datepart=[string], date1=[any], date2=[any])
```
### Arguments
| Argument | Type | Required | Description | Default |
| ---------- | -------- | -------- | ----------------------------------------------------------------------------------------------- | ------- |
| `datepart` | `string` | `true` | The datepart code in which to express the difference (yyyy, q, m, d, y, w, ww, wd, h, n, s, l). | |
| `date1` | `any` | `true` | The reference date object | |
| `date2` | `any` | `true` | The date which to compare against date1 | |
## Examples
### dateDiff Example
Find the difference between two dates.
[Run Example](https://try.boxlang.io/?code=eJxLSSxJdclMS9NQUEpR0lFQMjIwNNY1MNQ1NEXmGZkqKWhacwEA%2FP0JhQ%3D%3D)
```java
dateDiff( "d", "2013-01-15", "2013-01-25" );
```
Result: 10
### How old are they?
Calculates a persons age based on a variable birthDate which contains a date. Uses the now function to get current date.
[Run Example](https://try.boxlang.io/?code=eJxLyiwqyXBJLElVsFVILkoFMkAcDQVDS3MjHQVTHQUjAwVNa67EdJCCFJB0ZlqahoJSJRAo6SgkwbTrKOTll2togtSWF2WWpOaXlhSUlmgogDQCxQBb5x9R)
```java
birthDate = createDate( 1972, 5, 20 );
age = dateDiff( "yyyy", birthDate, now() );
writeoutput( age );
```
### dateDiff member function
[Run Example](https://try.boxlang.io/?code=eJw9jEsKg0AQRPeeonA1wiTiOrgICa6EnEHSLQ6EnjDTjdf3g7oqePWqlLO%2BB2W0kDi76lFQGMeD0BpPIoeSSo%2FGQ0979eYUlD%2Bmf1N3FfdtffjXUbXpqGvoFDISqyXJaBAFvX2ZPQYh3Hbwij%2FqLIcoxQLZ7DCY)
```java
testDate = now();
diffDate = dateAdd( "d", 1, testDate );
writeOutput( testDate.diff( "d", diffDate ) );
```
### Additional Examples
[Run Example](https://try.boxlang.io/?code=eJxLTc7I11BwSSxJdclMS9NQUEpR0lFQMjIwNNM1MNM1MkfhWSgpaCqoKSjZJBXZAZnWCvr6CoZcqaQYYY7FCAPSjDDDYoQuFmdkoJqhYGBgBUbowoZQYaL8RqyhBjgNxeJbDEMNSTUUm%2F%2FLUwi61RxPAHCBzDUy4gIAgmpzzQ%3D%3D)
```java
echo( DateDiff( "d", "2016-06-27", "2016-06-28" ) & "
" ); // 1
echo( DateDiff( "d", "2016-06-27", "2016-06-27" ) & "
" ); // 0
echo( DateDiff( "d", "2016-06-27", "2016-06-26" ) & "
" ); // -1
echo( DateDiff( "h", "2016-06-27 00:00:00", "2016-06-27 01:00:00" ) & "
" ); // 1
echo( DateDiff( "h", "2016-06-27 00:00:00", "2016-06-27 00:00:00" ) & "
" ); // 0
echo( DateDiff( "h", "2016-06-27 01:00:00", "2016-06-27 00:00:00" ) & "
" ); // -1
echo( DateDiff( "wd", "2016-06-27 00:00:00", "2016-07-27 01:00:00" ) & "
" );
// 22
```
## Related
* [ClearTimezone](/boxlang-language/reference/built-in-functions/temporal/cleartimezone.md)
* [CreateDate](/boxlang-language/reference/built-in-functions/temporal/createdate.md)
* [CreateDateTime](/boxlang-language/reference/built-in-functions/temporal/createdatetime.md)
* [CreateODBCDate](/boxlang-language/reference/built-in-functions/temporal/createodbcdate.md)
* [CreateODBCDateTime](/boxlang-language/reference/built-in-functions/temporal/createodbcdatetime.md)
* [CreateODBCTime](/boxlang-language/reference/built-in-functions/temporal/createodbctime.md)
* [CreateTime](/boxlang-language/reference/built-in-functions/temporal/createtime.md)
* [CreateTimeSpan](/boxlang-language/reference/built-in-functions/temporal/createtimespan.md)
* [DateAdd](/boxlang-language/reference/built-in-functions/temporal/dateadd.md)
* [DateCompare](/boxlang-language/reference/built-in-functions/temporal/datecompare.md)
* [DateConvert](/boxlang-language/reference/built-in-functions/temporal/dateconvert.md)
* [DateFormat](/boxlang-language/reference/built-in-functions/temporal/dateformat.md)
* [DatePart](/boxlang-language/reference/built-in-functions/temporal/datepart.md)
* [dateSetDay](/boxlang-language/reference/built-in-functions/temporal/datesetday.md)
* [dateSetHour](/boxlang-language/reference/built-in-functions/temporal/datesethour.md)
* [dateSetMinute](/boxlang-language/reference/built-in-functions/temporal/datesetminute.md)
* [dateSetMonth](/boxlang-language/reference/built-in-functions/temporal/datesetmonth.md)
* [dateSetSecond](/boxlang-language/reference/built-in-functions/temporal/datesetsecond.md)
* [dateSetYear](/boxlang-language/reference/built-in-functions/temporal/datesetyear.md)
* [DateTimeFormat](/boxlang-language/reference/built-in-functions/temporal/datetimeformat.md)
* [Day](/boxlang-language/reference/built-in-functions/temporal/day.md)
* [DayOfWeek](/boxlang-language/reference/built-in-functions/temporal/dayofweek.md)
* [DayOfWeekAsString](/boxlang-language/reference/built-in-functions/temporal/dayofweekasstring.md)
* [DayOfWeekShortAsString](/boxlang-language/reference/built-in-functions/temporal/dayofweekshortasstring.md)
* [DayOfYear](/boxlang-language/reference/built-in-functions/temporal/dayofyear.md)
* [DaysInMonth](/boxlang-language/reference/built-in-functions/temporal/daysinmonth.md)
* [DaysInYear](/boxlang-language/reference/built-in-functions/temporal/daysinyear.md)
* [FirstDayOfMonth](/boxlang-language/reference/built-in-functions/temporal/firstdayofmonth.md)
* [GetNumericDate](/boxlang-language/reference/built-in-functions/temporal/getnumericdate.md)
* [GetTime](/boxlang-language/reference/built-in-functions/temporal/gettime.md)
* [GetTimezone](/boxlang-language/reference/built-in-functions/temporal/gettimezone.md)
* [GetTimezoneInfo](/boxlang-language/reference/built-in-functions/temporal/gettimezoneinfo.md)
* [Hour](/boxlang-language/reference/built-in-functions/temporal/hour.md)
* [Millisecond](/boxlang-language/reference/built-in-functions/temporal/millisecond.md)
* [Minute](/boxlang-language/reference/built-in-functions/temporal/minute.md)
* [Month](/boxlang-language/reference/built-in-functions/temporal/month.md)
* [MonthAsString](/boxlang-language/reference/built-in-functions/temporal/monthasstring.md)
* [MonthShortAsString](/boxlang-language/reference/built-in-functions/temporal/monthshortasstring.md)
* [Nanosecond](/boxlang-language/reference/built-in-functions/temporal/nanosecond.md)
* [Now](/boxlang-language/reference/built-in-functions/temporal/now.md)
* [Offset](/boxlang-language/reference/built-in-functions/temporal/offset.md)
* [ParseDateTime](/boxlang-language/reference/built-in-functions/temporal/parsedatetime.md)
* [Quarter](/boxlang-language/reference/built-in-functions/temporal/quarter.md)
* [Second](/boxlang-language/reference/built-in-functions/temporal/second.md)
* [SetTimezone](/boxlang-language/reference/built-in-functions/temporal/settimezone.md)
* [TimeFormat](/boxlang-language/reference/built-in-functions/temporal/timeformat.md)
* [TimeUnits](/boxlang-language/reference/built-in-functions/temporal/timeunits.md)
* [Week](/boxlang-language/reference/built-in-functions/temporal/week.md)
* [Year](/boxlang-language/reference/built-in-functions/temporal/year.md)
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