new Clock(optionsopt)
    A simple clock for keeping track of simulated time.
    Parameters:
| Name | Type | Attributes | Description | |||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| options | Object | <optional> | Object with the following properties: Properties
 | 
- Source:
- See:
- 
        - ClockStep
- ClockRange
- JulianDate
 
Throws:
- 
        startTime must come before stopTime.
- Type
- DeveloperError
Example
// Create a clock that loops on Christmas day 2013 and runs in real-time.
var clock = new Cesium.Clock({
   startTime : Cesium.JulianDate.fromIso8601("2013-12-25"),
   currentTime : Cesium.JulianDate.fromIso8601("2013-12-25"),
   stopTime : Cesium.JulianDate.fromIso8601("2013-12-26"),
   clockRange : Cesium.ClockRange.LOOP_STOP,
   clockStep : Cesium.ClockStep.SYSTEM_CLOCK_MULTIPLIER
});Members
canAnimate :Boolean
    Indicates whether 
    Clock#tick can advance time.  This could be false if data is being buffered,
for example.  The clock will only advance time when both
Clock#canAnimate and Clock#shouldAnimate are true.
Type:
- Boolean
- Default Value:
- true
 
- Source:
clockRange :ClockRange
    Determines how the clock should behave when
    Clock#startTime or Clock#stopTime
is reached.
Type:
- ClockRange
- Default Value:
- ClockRange.UNBOUNDED
 
- Source:
clockStep :ClockStep
    Determines if calls to 
    Clock#tick are frame dependent or system clock dependent.
Changing this property to ClockStep.SYSTEM_CLOCK will set
Clock#multiplier to 1.0, Clock#shouldAnimate to true, and
Clock#currentTime to the current system clock time.
Type:
- ClockStep
- Default Value:
- ClockStep.SYSTEM_CLOCK_MULTIPLIER
 
- Source:
currentTime :JulianDate
    The current time.
Changing this property will change
    Clock#clockStep from ClockStep.SYSTEM_CLOCK to
ClockStep.SYSTEM_CLOCK_MULTIPLIER.
Type:
- Source:
multiplier :Number
    Gets or sets how much time advances when 
    Clock#tick is called. Negative values allow for advancing backwards.
If Clock#clockStep is set to ClockStep.TICK_DEPENDENT, this is the number of seconds to advance.
If Clock#clockStep is set to ClockStep.SYSTEM_CLOCK_MULTIPLIER, this value is multiplied by the
elapsed system time since the last call to Clock#tick.
Changing this property will change
Clock#clockStep from ClockStep.SYSTEM_CLOCK to
ClockStep.SYSTEM_CLOCK_MULTIPLIER.
Type:
- Number
- Default Value:
- 1.0
 
- Source:
onTick :Event
    An 
    Event that is fired whenever Clock#tick is called.
Type:
- Source:
shouldAnimate :Boolean
    Indicates whether 
    Clock#tick should attempt to advance time.
The clock will only advance time when both
Clock#canAnimate and Clock#shouldAnimate are true.
Changing this property will change
Clock#clockStep from ClockStep.SYSTEM_CLOCK to
ClockStep.SYSTEM_CLOCK_MULTIPLIER.
Type:
- Boolean
- Default Value:
- true
 
- Source:
startTime :JulianDate
    The start time of the clock.
    Type:
- Source:
stopTime :JulianDate
    The stop time of the clock.
    Type:
- Source:
Methods
tick() → {JulianDate}
    Advances the clock from the current time based on the current configuration options.
tick should be called every frame, regardless of whether animation is taking place
or not.  To control animation, use the 
Clock#shouldAnimate property.
- Source:
Returns:
    The new value of the 
Clock#currentTime property.
- Type
- JulianDate