# 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`   |                                         |         |
| `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" ) & "<br>" ); // 1
echo( DateDiff( "d", "2016-06-27", "2016-06-27" ) & "<br>" ); // 0
echo( DateDiff( "d", "2016-06-27", "2016-06-26" ) & "<br>" ); // -1
echo( DateDiff( "h", "2016-06-27 00:00:00", "2016-06-27 01:00:00" ) & "<br>" ); // 1
echo( DateDiff( "h", "2016-06-27 00:00:00", "2016-06-27 00:00:00" ) & "<br>" ); // 0
echo( DateDiff( "h", "2016-06-27 01:00:00", "2016-06-27 00:00:00" ) & "<br>" ); // -1
echo( DateDiff( "wd", "2016-06-27 00:00:00", "2016-07-27 01:00:00" ) & "<br>" );
 // 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)
* [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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