```
public interface Clock
```
Accurately simulating time-dependent behavior is essential for verifying the correctness of applications. Learn more about clock emulation.
Note that clock is installed for the entire BrowserContext, so the time in all the pages and iframes is controlled by the same clock.

Nested Class Summary

Nested Classes
Modifier and Type Interface Description

static class Clock.InstallOptions

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`void`	`fastForward(long ticks)`	Advance the clock by jumping forward in time.
`void`	`fastForward(String ticks)`	Advance the clock by jumping forward in time.
`default void`	`install()`	Install fake implementations for the following time-related functions: `Date` `setTimeout` `clearTimeout` `setInterval` `clearInterval` `requestAnimationFrame` `cancelAnimationFrame` `requestIdleCallback` `cancelIdleCallback` `performance`
`void`	`install(Clock.InstallOptions options)`	Install fake implementations for the following time-related functions: `Date` `setTimeout` `clearTimeout` `setInterval` `clearInterval` `requestAnimationFrame` `cancelAnimationFrame` `requestIdleCallback` `cancelIdleCallback` `performance`
`void`	`pauseAt(long time)`	Advance the clock by jumping forward in time and pause the time.
`void`	`pauseAt(String time)`	Advance the clock by jumping forward in time and pause the time.
`void`	`pauseAt(Date time)`	Advance the clock by jumping forward in time and pause the time.
`void`	`resume()`	Resumes timers.
`void`	`runFor(long ticks)`	Advance the clock, firing all the time-related callbacks.
`void`	`runFor(String ticks)`	Advance the clock, firing all the time-related callbacks.
`void`	`setFixedTime(long time)`	Makes `Date.now` and `new Date()` return fixed fake time at all times, keeps all the timers running.
`void`	`setFixedTime(String time)`	Makes `Date.now` and `new Date()` return fixed fake time at all times, keeps all the timers running.
`void`	`setFixedTime(Date time)`	Makes `Date.now` and `new Date()` return fixed fake time at all times, keeps all the timers running.
`void`	`setSystemTime(long time)`	Sets current system time but does not trigger any timers.
`void`	`setSystemTime(String time)`	Sets current system time but does not trigger any timers.
`void`	`setSystemTime(Date time)`	Sets current system time but does not trigger any timers.

- Method Detail
  - fastForward
```
void fastForward(long ticks)
```
    Advance the clock by jumping forward in time. Only fires due timers at most once. This is equivalent to user closing the laptop lid for a while and reopening it later, after given time.
    Usage
    page.clock().fastForward(1000); page.clock().fastForward("30:00");
    Parameters:
    
    ticks - Time may be the number of milliseconds to advance the clock by or a human-readable string. Valid string formats are "08" for eight seconds, "01:00" for one minute and "02:34:10" for two hours, 34 minutes and ten seconds.
    
    Since:
    
    v1.45
  - fastForward
```
void fastForward(String ticks)
```
    Advance the clock by jumping forward in time. Only fires due timers at most once. This is equivalent to user closing the laptop lid for a while and reopening it later, after given time.
    Usage
    page.clock().fastForward(1000); page.clock().fastForward("30:00");
    Parameters:
    
    ticks - Time may be the number of milliseconds to advance the clock by or a human-readable string. Valid string formats are "08" for eight seconds, "01:00" for one minute and "02:34:10" for two hours, 34 minutes and ten seconds.
    
    Since:
    
    v1.45
  - install
```
default void install()
```
    Install fake implementations for the following time-related functions:
    
    Date
    
    setTimeout
    
    clearTimeout
    
    setInterval
    
    clearInterval
    
    requestAnimationFrame
    
    cancelAnimationFrame
    
    requestIdleCallback
    
    cancelIdleCallback
    
    performance
    
    Fake timers are used to manually control the flow of time in tests. They allow you to advance time, fire timers, and control the behavior of time-dependent functions. See Clock.runFor() and Clock.fastForward() for more information.
    Since:
    
    v1.45
  - install
```
void install(Clock.InstallOptions options)
```
    Install fake implementations for the following time-related functions:
    
    Date
    
    setTimeout
    
    clearTimeout
    
    setInterval
    
    clearInterval
    
    requestAnimationFrame
    
    cancelAnimationFrame
    
    requestIdleCallback
    
    cancelIdleCallback
    
    performance
    
    Fake timers are used to manually control the flow of time in tests. They allow you to advance time, fire timers, and control the behavior of time-dependent functions. See Clock.runFor() and Clock.fastForward() for more information.
    Since:
    
    v1.45
  - runFor
```
void runFor(long ticks)
```
    Advance the clock, firing all the time-related callbacks.
    Usage
    page.clock().runFor(1000); page.clock().runFor("30:00");
    Parameters:
    
    ticks - Time may be the number of milliseconds to advance the clock by or a human-readable string. Valid string formats are "08" for eight seconds, "01:00" for one minute and "02:34:10" for two hours, 34 minutes and ten seconds.
    
    Since:
    
    v1.45
  - runFor
```
void runFor(String ticks)
```
    Advance the clock, firing all the time-related callbacks.
    Usage
    page.clock().runFor(1000); page.clock().runFor("30:00");
    Parameters:
    
    ticks - Time may be the number of milliseconds to advance the clock by or a human-readable string. Valid string formats are "08" for eight seconds, "01:00" for one minute and "02:34:10" for two hours, 34 minutes and ten seconds.
    
    Since:
    
    v1.45
  - pauseAt
```
void pauseAt(long time)
```
    Advance the clock by jumping forward in time and pause the time. Once this method is called, no timers are fired unless Clock.runFor(), Clock.fastForward(), Clock.pauseAt() or Clock.resume() is called.
    Only fires due timers at most once. This is equivalent to user closing the laptop lid for a while and reopening it at the specified time and pausing.
    Usage
    SimpleDateFormat format = new SimpleDateFormat("yyy-MM-dd"); page.clock().pauseAt(format.parse("2020-02-02")); page.clock().pauseAt("2020-02-02");
    Parameters:
    
    time - Time to pause at.
    
    Since:
    
    v1.45
  - pauseAt
```
void pauseAt(String time)
```
    Advance the clock by jumping forward in time and pause the time. Once this method is called, no timers are fired unless Clock.runFor(), Clock.fastForward(), Clock.pauseAt() or Clock.resume() is called.
    Only fires due timers at most once. This is equivalent to user closing the laptop lid for a while and reopening it at the specified time and pausing.
    Usage
    SimpleDateFormat format = new SimpleDateFormat("yyy-MM-dd"); page.clock().pauseAt(format.parse("2020-02-02")); page.clock().pauseAt("2020-02-02");
    Parameters:
    
    time - Time to pause at.
    
    Since:
    
    v1.45
  - pauseAt
```
void pauseAt(Date time)
```
    Advance the clock by jumping forward in time and pause the time. Once this method is called, no timers are fired unless Clock.runFor(), Clock.fastForward(), Clock.pauseAt() or Clock.resume() is called.
    Only fires due timers at most once. This is equivalent to user closing the laptop lid for a while and reopening it at the specified time and pausing.
    Usage
    SimpleDateFormat format = new SimpleDateFormat("yyy-MM-dd"); page.clock().pauseAt(format.parse("2020-02-02")); page.clock().pauseAt("2020-02-02");
    Parameters:
    
    time - Time to pause at.
    
    Since:
    
    v1.45
  - resume
```
void resume()
```
    Resumes timers. Once this method is called, time resumes flowing, timers are fired as usual.
    
    Since:
    
    v1.45
  - setFixedTime
```
void setFixedTime(long time)
```
    Makes Date.now and new Date() return fixed fake time at all times, keeps all the timers running.
    Usage
    page.clock().setFixedTime(new Date()); page.clock().setFixedTime(new SimpleDateFormat("yyy-MM-dd").parse("2020-02-02")); page.clock().setFixedTime("2020-02-02");
    Parameters:
    
    time - Time to be set in milliseconds.
    
    Since:
    
    v1.45
  - setFixedTime
```
void setFixedTime(String time)
```
    Makes Date.now and new Date() return fixed fake time at all times, keeps all the timers running.
    Usage
    page.clock().setFixedTime(new Date()); page.clock().setFixedTime(new SimpleDateFormat("yyy-MM-dd").parse("2020-02-02")); page.clock().setFixedTime("2020-02-02");
    Parameters:
    
    time - Time to be set in milliseconds.
    
    Since:
    
    v1.45
  - setFixedTime
```
void setFixedTime(Date time)
```
    Makes Date.now and new Date() return fixed fake time at all times, keeps all the timers running.
    Usage
    page.clock().setFixedTime(new Date()); page.clock().setFixedTime(new SimpleDateFormat("yyy-MM-dd").parse("2020-02-02")); page.clock().setFixedTime("2020-02-02");
    Parameters:
    
    time - Time to be set in milliseconds.
    
    Since:
    
    v1.45
  - setSystemTime
```
void setSystemTime(long time)
```
    Sets current system time but does not trigger any timers.
    Usage
    page.clock().setSystemTime(new Date()); page.clock().setSystemTime(new SimpleDateFormat("yyy-MM-dd").parse("2020-02-02")); page.clock().setSystemTime("2020-02-02");
    Parameters:
    
    time - Time to be set in milliseconds.
    
    Since:
    
    v1.45
  - setSystemTime
```
void setSystemTime(String time)
```
    Sets current system time but does not trigger any timers.
    Usage
    page.clock().setSystemTime(new Date()); page.clock().setSystemTime(new SimpleDateFormat("yyy-MM-dd").parse("2020-02-02")); page.clock().setSystemTime("2020-02-02");
    Parameters:
    
    time - Time to be set in milliseconds.
    
    Since:
    
    v1.45
  - setSystemTime
```
void setSystemTime(Date time)
```
    Sets current system time but does not trigger any timers.
    Usage
    page.clock().setSystemTime(new Date()); page.clock().setSystemTime(new SimpleDateFormat("yyy-MM-dd").parse("2020-02-02")); page.clock().setSystemTime("2020-02-02");
    Parameters:
    
    time - Time to be set in milliseconds.
    
    Since:
    
    v1.45

Interface Clock

Nested Class Summary

Method Summary

Method Detail

fastForward

fastForward

install

install

runFor

runFor

pauseAt

pauseAt

pauseAt

resume

setFixedTime

setFixedTime

setFixedTime

setSystemTime

setSystemTime

setSystemTime