Function Repository Resource:

PauseUntil

Source Notebook

Pause evaluation until a given time

Contributed by: Daniele Gregori

ResourceFunction["PauseUntil"][string]

pauses until a given time, specified as String.

ResourceFunction["PauseUntil"][time]

pauses until a given TimeObject.

ResourceFunction["PauseUntil"][date]

pauses until a given DateObject.

Details and Options

While the basic function Pause halts code execution for a certain number of seconds, ResourceFunction["PauseUntil"] halts it until a certain given time occurs.

Possible arguments of ResourceFunction["PauseUntil"] are: TimeObject, DateObject, or String, the last of which is automatically interpreted as either a "Time", "Date", or "DateTime".

ResourceFunction["PauseUntil"] accepts the following options:

TimeZone

Automatic

the time zone used in all the internal evaluations

"PauseInformation"

False

whether to Echo the time to be paused

"Periodicity"

None

consider the input as a periodically repeating time

There is no output for ResourceFunction["PauseUntil"], but the time to be waited for can be echoed by setting the option "PauseInformation" to True.

The values for the option "Periodicity" can be:

None

pause until only the specified time

pause until the next occurrence of the given time repeated in the future every n days

{n,unit}

pause until the next occurrence of the given time repeated in the future every n integer units of time

The unit in the "Periodicity" option value can be one of the following: "Year", "Quarter", "Month", "Week", "Day", "Hour", "Minute", "Second", "Weekday", "Weekend", Monday through Sunday, "EndOfMonth", "BeginningOfMonth" and "BusinessDay".

Normally, entering as input past times leads to failure, unless the option "Periodicity" is set. Then a past date or time is interpreted as periodically repeating every n*unit time in the future and the evaluation pauses until the next occurrence of such periodic date.

A potential application of ResourceFunction["PauseUntil"] is for setting up scheduled tasks running at fixed times, especially on remote servers using the Wolfram Engine.

Other use cases include API rate limiting, external coordination, simulations or demonstrations.

Examples

Basic Examples (2)

Pause evaluation until a certain time:

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Pause until a certain date-time:

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Scope (3)

Specify the time zone:

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Pause until a time specified by TimeObject:

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Pause until a time specified as a DateObject:

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Options (4)

TimeZone (1)

Specify the TimeZone as an option:

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$ResourceFunction["PauseUntil"][TimeObject[{7, 30}], TimeZone -> "America/Los_Angeles"]$

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PauseInformation (1)

Sometimes it can be useful to get information, through Echo, on the total seconds to be waited:

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Periodicity (2)

A past date argument is interpreted as a periodic date recurring cyclically in the future.

Pause until the next occurrence of a certain time recurring every day in the future:

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Pause until the next occurrence of a certain time recurring every n units of time:

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Applications (2)

PauseUntil[time] can be used to implement scheduled tasks.

For example, collect SunPosition data every 15 minutes from 1 pm to 2 pm:

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ResourceFunction["PauseUntil"][time]

Do[
AppendTo[sundata, TimeObject[] -> SunPosition[]];
ResourceFunction["PauseUntil"][time, "Periodicity" -> {15, "Minute"}], 4];

sundata = Append[sundata, TimeObject[] -> SunPosition[]] // Association

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Plot the collected data points and their fit curve:

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Properties and Relations (2)

If the specified TimeObject lies in the latter part of the day, PauseUntil[time] is equivalent to Pause[QuantityMagnitude[DateDifference[Now,time,"Seconds"]]]:

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If the specified TimeObject lies in the earlier part of the day PauseUntil[time] is equivalent to 86400-QuantityMagnitude[DateDifference[time,Now,"Seconds"]]: