Internationalisation
Bundled Plugins API
timer
Execute functions with various timing rules
NOTE: timers use NSTimer internally, which will be paused when computers sleep. Especially, repeating timers won't be triggered at the specificed time when there are sleeps in between. The workaround is to prevent system from sleeping, configured in Energy Saver in System Preferences.

Submodules

API Overview

API Documentation

Functions

Signature
hs.timer.absoluteTime() -> nanoseconds
Type
Function
Description
Returns the absolute time in nanoseconds since the last system boot.
Parameters
  • None
Returns
  • the time since the last system boot in nanoseconds
Notes
  • this value does not include time that the system has spent asleep
  • this value is used for the timestamps in system generated events.

days

Signature
hs.timer.days(n) -> sec
Type
Function
Description
Converts days to seconds
Parameters
  • n - A number of days
Returns
  • The number of seconds in n days

hours

Signature
hs.timer.hours(n) -> seconds
Type
Function
Description
Converts hours to seconds
Parameters
  • n - A number of hours
Returns
  • The number of seconds in n hours

localTime

Signature
hs.timer.localTime() -> number
Type
Function
Description
Returns the number of seconds since local time midnight
Parameters
  • None
Returns
  • the number of seconds

minutes

Signature
hs.timer.minutes(n) -> seconds
Type
Function
Description
Converts minutes to seconds
Parameters
  • n - A number of minutes
Returns
  • The number of seconds in n minutes

seconds

Signature
hs.timer.seconds(timeOrDuration) -> seconds
Type
Function
Description
Converts a string with a time of day or a duration into number of seconds
Parameters
  • timeOrDuration - a string that can have any of the following formats:
  • "HH:MM:SS" or "HH:MM" - represents a time of day (24-hour clock), returns the number of seconds since midnight
  • "DDdHHh", "HHhMMm", "MMmSSs", "DDd", "HHh", "MMm", "SSs", "NNNNms" - represents a duration in days, hours, minutes, seconds and/or milliseconds
Returns
  • The number of seconds
Signature
hs.timer.secondsSinceEpoch() -> sec
Type
Function
Description
Gets the (fractional) number of seconds since the UNIX epoch (January 1, 1970)
Parameters
  • None
Returns
  • The number of seconds since the epoch
Notes
  • This has much better precision than os.time(), which is limited to whole seconds.

usleep

Signature
hs.timer.usleep(microsecs)
Type
Function
Description
Blocks Lua execution for the specified time
Parameters
  • microsecs - A number containing a time in microseconds to block for
Returns
  • None
Notes
  • Use of this function is strongly discouraged, as it blocks all main-thread execution in Hammerspoon. This means no hotkeys or events will be processed in that time, no GUI updates will happen, and no Lua will execute. This is only provided as a last resort, or for extremely short sleeps. For all other purposes, you really should be splitting up your code into multiple functions and calling hs.timer.doAfter()

weeks

Signature
hs.timer.weeks(n) -> sec
Type
Function
Description
Converts weeks to seconds
Parameters
  • n - A number of weeks
Returns
  • The number of seconds in n weeks

Constructors

doAfter

Signature
hs.timer.doAfter(sec, fn) -> timer
Type
Constructor
Description
Calls a function after a delay
Parameters
  • sec - A number of seconds to wait before calling the function
  • fn - A function to call
Returns
  • An hs.timer object
Notes
  • There is no need to call :start() on the returned object, the timer will be already running.
  • The callback can be cancelled by calling the :stop() method on the returned object before sec seconds have passed.

doAt

Signature
hs.timer.doAt(time[, repeatInterval], fn[, continueOnError]) -> timer
Type
Constructor
Description
Creates and starts a timer which will perform fn at the given (local) time and then (optionally) repeat it every interval.
Parameters
  • time - number of seconds after (local) midnight, or a string in the format "HH:MM" (24-hour local time), indicating the desired trigger time
  • repeatInterval - (optional) number of seconds between triggers, or a string in the format "DDd", "DDdHHh", "HHhMMm", "HHh" or "MMm" indicating days, hours and/or minutes between triggers; if omitted or 0 the timer will trigger only once
  • fn - a function to call every time the timer triggers
  • continueOnError - an optional boolean flag, defaulting to false, which indicates that the timer should not be automatically stopped if the callback function results in an error.
Returns
  • a timer object
Notes
  • The timer can trigger up to 1 second early or late
  • The first trigger will be set to the earliest occurrence given the repeatInterval; if that's omitted, and time is earlier than the current time, the timer will trigger the next day. If the repeated interval results in exactly 24 hours you can schedule regular jobs that will run at the expected time independently of when Hammerspoon was restarted/reloaded. E.g.:
  • If it's 19:00, hs.timer.doAt("20:00",somefn) will set the timer 1 hour from now
  • If it's 21:00, hs.timer.doAt("20:00",somefn) will set the timer 23 hours from now
  • If it's 21:00, hs.timer.doAt("20:00","6h",somefn) will set the timer 5 hours from now (at 02:00)
  • To run a job every hour on the hour from 8:00 to 20:00: for h=8,20 do hs.timer.doAt(h..":00","1d",runJob) end

doEvery

Signature
hs.timer.doEvery(interval, fn) -> timer
Type
Constructor
Description
Repeats fn every interval seconds.
Parameters
  • interval - A number of seconds between triggers
  • fn - A function to call every time the timer triggers
Returns
  • An hs.timer object
Notes
  • This function is a shorthand for hs.timer.new(interval, fn):start()

doUntil

Signature
hs.timer.doUntil(predicateFn, actionFn[, checkInterval]) -> timer
Type
Constructor
Description
Creates and starts a timer which will perform actionFn every checkinterval seconds until predicateFn returns true. The timer is automatically stopped when predicateFn returns true.
Parameters
  • predicateFn - a function which determines when to stop calling actionFn. This function takes no arguments, but should return true when it is time to stop calling actionFn.
  • actionFn - a function which performs the desired action. This function may take a single argument, the timer itself.
  • checkInterval - an optional parameter indicating how often to repeat the predicateFn check. Defaults to 1 second.
Returns
  • a timer object
Notes
  • The timer is passed as an argument to actionFn so that it may stop the timer prematurely (i.e. before predicateFn returns true) if desired.
  • See also hs.timer.doWhile, which is essentially the opposite of this function

doWhile

Signature
hs.timer.doWhile(predicateFn, actionFn[, checkInterval]) -> timer
Type
Constructor
Description
Creates and starts a timer which will perform actionFn every checkinterval seconds while predicateFn returns true. The timer is automatically stopped when predicateFn returns false.
Parameters
  • predicateFn - a function which determines when to stop calling actionFn. This function takes no arguments, but should return false when it is time to stop calling actionFn.
  • actionFn - a function which performs the desired action. This function may take a single argument, the timer itself.
  • checkInterval - an optional parameter indicating how often to repeat the predicateFn check. Defaults to 1 second.
Returns
  • a timer object
Notes
  • The timer is passed as an argument to actionFn so that it may stop the timer prematurely (i.e. before predicateFn returns false) if desired.
  • See also hs.timer.doUntil, which is essentially the opposite of this function

new

Signature
hs.timer.new(interval, fn [, continueOnError]) -> timer
Type
Constructor
Description
Creates a new hs.timer object for repeating interval callbacks
Parameters
  • interval - A number of seconds between firings of the timer
  • fn - A function to call every time the timer fires
  • continueOnError - An optional boolean, true if the timer should continue to be triggered after the callback function has produced an error, false if the timer should stop being triggered after the callback function has produced an error. Defaults to false.
Returns
  • An hs.timer object
Notes
  • The returned object does not start its timer until its :start() method is called
  • If interval is 0, the timer will not repeat (because if it did, it would be repeating as fast as your machine can manage, which seems generally unwise)
  • For non-zero intervals, the lowest acceptable value for the interval is 0.00001s. Values >0 and <0.00001 will be coerced to 0.00001

waitUntil

Signature
hs.timer.waitUntil(predicateFn, actionFn[, checkInterval]) -> timer
Type
Constructor
Description
Creates and starts a timer which will perform actionFn when predicateFn returns true. The timer is automatically stopped when actionFn is called.
Parameters
  • predicateFn - a function which determines when actionFn should be called. This function takes no arguments, but should return true when it is time to call actionFn.
  • actionFn - a function which performs the desired action. This function may take a single argument, the timer itself.
  • checkInterval - an optional parameter indicating how often to repeat the predicateFn check. Defaults to 1 second.
Returns
  • a timer object
Notes
  • The timer is stopped before actionFn is called, but the timer is passed as an argument to actionFn so that the actionFn may restart the timer to be called again the next time predicateFn returns true.
  • See also hs.timer.waitWhile, which is essentially the opposite of this function

waitWhile

Signature
hs.timer.waitWhile(predicateFn, actionFn[, checkInterval]) -> timer
Type
Constructor
Description
Creates and starts a timer which will perform actionFn when predicateFn returns false. The timer is automatically stopped when actionFn is called.
Parameters
  • predicateFn - a function which determines when actionFn should be called. This function takes no arguments, but should return false when it is time to call actionFn.
  • actionFn - a function which performs the desired action. This function may take a single argument, the timer itself.
  • checkInterval - an optional parameter indicating how often to repeat the predicateFn check. Defaults to 1 second.
Returns
  • a timer object
Notes
  • The timer is stopped before actionFn is called, but the timer is passed as an argument to actionFn so that the actionFn may restart the timer to be called again the next time predicateFn returns false.
  • See also hs.timer.waitUntil, which is essentially the opposite of this function

Methods

fire

Signature
hs.timer:fire() -> timer
Type
Method
Description
Immediately fires a timer
Parameters
  • None
Returns
  • The hs.timer object
Notes
  • This cannot be used on a timer which has already stopped running
Signature
hs.timer:nextTrigger() -> number
Type
Method
Description
Returns the number of seconds until the timer will next trigger
Parameters
  • None
Returns
  • A number containing the number of seconds until the next firing
Notes
  • The return value may be a negative integer in two circumstances:
  • Hammerspoon's runloop is backlogged and is catching up on missed timer triggers
  • The timer object is not currently running. In this case, the return value of this method is the number of seconds since the last firing (you can check if the timer is running or not, with hs.timer:running()

running

Signature
hs.timer:running() -> boolean
Type
Method
Description
Returns a boolean indicating whether or not the timer is currently running.
Parameters
  • None
Returns
  • A boolean value indicating whether or not the timer is currently running.
Signature
hs.timer:setNextTrigger(seconds) -> timer
Type
Method
Description
Sets the next trigger time of a timer
Parameters
  • seconds - A number of seconds after which to trigger the timer
Returns
  • The hs.timer object, or nil if an error occurred
Notes
  • If the timer is not already running, this will start it

start

Signature
hs.timer:start() -> timer
Type
Method
Description
Starts an hs.timer object
Parameters
  • None
Returns
  • The hs.timer object
Notes
  • The timer will not call the callback immediately, the timer will wait until it fires
  • If the callback function results in an error, the timer will be stopped to prevent repeated error notifications (see the continueOnError parameter to hs.timer.new() to override this)

stop

Signature
hs.timer:stop() -> timer
Type
Method
Description
Stops an hs.timer object
Parameters
  • None
Returns
  • The hs.timer object
Last modified 1mo ago