# Duration

The `Duration` class is designed to represent a time-based duration, typically measured in seconds and nanoseconds. It offers a range of static methods for creating durations based on days, hours, minutes, seconds, milliseconds, and nanoseconds. Additionally, it provides conversion methods to express the duration in various units, as well as the ability to calculate the duration between two temporal objects. This class is ideal for measuring time spans, tracking elapsed time, and performing time-based calculations in applications.

### Static Methods

#### `ofDays(days: Long)`

* Obtains a `Duration` representing a number of standard 24-hour days.
* Example Usage:

  ```java
  var daysDuration = Duration.ofDays(5);
  ```

#### `ofHours(hours: Long)`

* Obtains a `Duration` representing a number of standard hours.
* Example Usage:

  ```java
  var hoursDuration = Duration.ofHours(12);
  ```

#### `ofMinutes(minutes: Long)`

* Obtains a `Duration` representing a number of standard minutes.
* Example Usage:

  ```java
  var minutesDuration = Duration.ofMinutes(30);
  ```

#### `ofSeconds(seconds: Long)`

* Obtains a `Duration` representing a number of seconds.
* Example Usage:

  ```java
  var secondsDuration = Duration.ofSeconds(120);
  ```

#### `ofMillis(millis: Long)`

* Obtains a `Duration` representing a number of milliseconds.
* Example Usage:

  ```java
  var millisDuration = Duration.ofMillis(5000);
  ```

#### `ofNanos(nanos: Long)`

* Obtains a `Duration` representing a number of nanoseconds.
* Example Usage:

  ```java
  var nanosDuration = Duration.ofNanos(123456789);
  ```

#### `parse(text: String)`

* Obtains a `Duration` from a text string such as `PnDTnHnMn.nS`.
* Parses a textual representation of a duration, including the string produced by `toString()`.
* Example Usage:

  ```java
  var parsedDuration = Duration.parse("PT20.345S");
  ```

### Conversion Methods

#### `toString()`

* A string representation of this duration using ISO-8601 seconds based representation, such as `PT8H6M12.345S`.
* Example Usage:

  ```java
  var stringRepresentation = parsedDuration.toString();
  ```

#### `toDays()`

* Gets the number of days in this duration.
* Example Usage:

  ```java
  var days = daysDuration.toDays();
  ```

#### `toHours()`

* Gets the number of hours in this duration.
* Example Usage:

  ```java
  var hours = hoursDuration.toHours();
  ```

#### `toMinutes()`

* Gets the number of minutes in this duration.
* Example Usage:

  ```java
  var minutes = minutesDuration.toMinutes();
  ```

#### `toSeconds()`

* Gets the number of seconds in this duration.
* Example Usage:

  ```java
  var seconds = secondsDuration.toSeconds();
  ```

#### `toMillis()`

* Converts this duration to the total length in milliseconds.
* Example Usage:

  ```java
  var millis = millisDuration.toMillis();
  ```

#### `toNanos()`

* Converts this duration to the total length in nanoseconds expressed as a `long`.
* Example Usage:

  ```java
  var nanos = nanosDuration.toNanos();
  ```

#### `between(startInclusive: any, endExclusive: any)`

* Obtains a `Duration` representing the duration between two temporal objects.
* Example Usage:

  ```java
  var start = LocalDateTime.now(); // current date-time
  var end = start.plusHours(2); // current date-time plus 2 hours
  var duration = Duration.between(start, end); // duration is 2 hours
  ```

### **Examples**

**Example: Days Ago**

**Description:** This script calculates the number of days between a specified ‘order\_date’ and the current date.

**Use Case:** Useful for tracking the time elapsed since an order was placed.

```javascript
var days = Duration.between(order_date.atStartOfDay(), 
                                LocalDate.now().atStartOfDay());

//Return the days as a number, we can also return toMinutes(), toYears(), ... as well
return days.toDays();
```

This example demonstrates how the Duration class can be used for tracking the age of data or calculating time-based metrics in various applications.