description

# Duration class

A span of time, such as 27 days, 4 hours, 12 minutes, and 3 seconds.

A `Duration` represents a difference from one point in time to another. The duration may be "negative" if the difference is from a later time to an earlier.

Durations are context independent. For example, a duration of 2 days is always 48 hours, even when it is added to a `DateTime` just when the time zone is about to make a daylight-savings switch. (See DateTime.add).

Despite the same name, a `Duration` object does not implement "Durations" as specified by ISO 8601. In particular, a duration object does not keep track of the individually provided members (such as "days" or "hours"), but only uses these arguments to compute the length of the corresponding time interval.

To create a new `Duration` object, use this class's single constructor giving the appropriate arguments:

    const fastestMarathon = Duration(hours: 2, minutes: 3, seconds: 2);

The Duration represents a single number of microseconds, which is the sum of all the individual arguments to the constructor.

Properties can access that single number in different ways. For example the inMinutes gives the number of whole minutes in the total duration, which includes the minutes that were provided as "hours" to the constructor, and can be larger than 59.

    const fastestMarathon = Duration(hours: 2, minutes: 0, seconds: 35);
    print(fastestMarathon.inDays); // 0
    print(fastestMarathon.inHours); // 2
    print(fastestMarathon.inMinutes); // 120
    print(fastestMarathon.inSeconds); // 7235
    print(fastestMarathon.inMilliseconds); // 7235000

The duration can be negative, in which case all the properties derived from the duration are also non-positive.

    const overDayAgo = Duration(days: -1, hours: -10);
    print(overDayAgo.inDays); // -1
    print(overDayAgo.inHours); // -34
    print(overDayAgo.inMinutes); // -2040

Use one of the properties, such as inDays, to retrieve the integer value of the `Duration` in the specified time unit. Note that the returned value is rounded down. For example,

    const aLongWeekend = Duration(hours: 88);
    print(aLongWeekend.inDays); // 3

This class provides a collection of arithmetic and comparison operators, plus a set of constants useful for converting time units.

    const firstHalf = Duration(minutes: 45); // 00:45:00.000000
    const secondHalf = Duration(minutes: 45); // 00:45:00.000000
    const overTime = Duration(minutes: 30); // 00:30:00.000000
    final maxGameTime = firstHalf + secondHalf + overTime;
    print(maxGameTime.inMinutes); // 120

    // The duration of the firstHalf and secondHalf is the same, returns 0.
    var result = firstHalf.compareTo(secondHalf);
    print(result); // 0

    // Duration of overTime is shorter than firstHalf, returns < 0.
    result = overTime.compareTo(firstHalf);
    print(result); // < 0

    // Duration of secondHalf is longer than overTime, returns > 0.
    result = secondHalf.compareTo(overTime);
    print(result); // > 0

See also:

- DateTime to represent a point in time.
- Stopwatch to measure time-spans.

Implemented types
  - Comparable<Duration>

## Constructors

Duration({int days = 0, int hours = 0, int minutes = 0, int seconds = 0, int milliseconds = 0, int microseconds = 0})
  Creates a new Duration object whose value is the sum of all individual parts.
  const

## Properties

hashCode → int
  The hash code for this object.
  no setteroverride
inDays → int
  The number of entire days spanned by this Duration.
  no setter
inHours → int
  The number of entire hours spanned by this Duration.
  no setter
inMicroseconds → int
  The number of whole microseconds spanned by this Duration.
  no setter
inMilliseconds → int
  The number of whole milliseconds spanned by this Duration.
  no setter
inMinutes → int
  The number of whole minutes spanned by this Duration.
  no setter
inSeconds → int
  The number of whole seconds spanned by this Duration.
  no setter
isNegative → bool
  Whether this Duration is negative.
  no setter
runtimeType → Type
  A representation of the runtime type of the object.
  no setterinherited

## Methods

abs() → Duration
  Creates a new Duration representing the absolute length of this Duration.
compareTo(Duration other) → int
  Compares this Duration to `other`, returning zero if the values are equal.
  override
noSuchMethod(Invocation invocation) → dynamic
  Invoked when a nonexistent method or property is accessed.
  inherited
toString() → String
  Returns a string representation of this Duration.
  override

## Operators

operator *(num factor) → Duration
  Multiplies this Duration by the given `factor` and returns the result as a new Duration object.
operator +(Duration other) → Duration
  Adds this Duration and `other` and returns the sum as a new Duration object.
operator -(Duration other) → Duration
  Subtracts `other` from this Duration and returns the difference as a new Duration object.
operator <(Duration other) → bool
  Whether this Duration is shorter than `other`.
operator <=(Duration other) → bool
  Whether this Duration is shorter than or equal to `other`.
operator ==(Object other) → bool
  Whether this Duration has the same length as `other`.
  override
operator >(Duration other) → bool
  Whether this Duration is longer than `other`.
operator >=(Duration other) → bool
  Whether this Duration is longer than or equal to `other`.
operator unary-() → Duration
  Creates a new Duration with the opposite direction of this Duration.
operator ~/(int quotient) → Duration
  Divides this Duration by the given `quotient` and returns the truncated result as a new Duration object.

## Constants

hoursPerDay → const int
  The number of hours per day.
microsecondsPerDay → const int
  The number of microseconds per day.
microsecondsPerHour → const int
  The number of microseconds per hour.
microsecondsPerMillisecond → const int
  The number of microseconds per millisecond.
microsecondsPerMinute → const int
  The number of microseconds per minute.
microsecondsPerSecond → const int
  The number of microseconds per second.
millisecondsPerDay → const int
  The number of milliseconds per day.
millisecondsPerHour → const int
  The number of milliseconds per hour.
millisecondsPerMinute → const int
  The number of milliseconds per minute.
millisecondsPerSecond → const int
  The number of milliseconds per second.
minutesPerDay → const int
  The number of minutes per day.
minutesPerHour → const int
  The number of minutes per hour.
secondsPerDay → const int
  The number of seconds per day.
secondsPerHour → const int
  The number of seconds per hour.
secondsPerMinute → const int
  The number of seconds per minute.
zero → const Duration
  An empty duration, representing zero time.