# Tagged Questions

Questions about Mathematica's date and time functions.

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### How to add new formula in existing formula in certain time?

Good day, May anyone help me to give an idea to edit the coding For as below towards my problems. β1 = 0; β3 = 0; β2 = Pi/2; For[t = 0, t < 30, t++, A = {{E^(Iβ1 + Iβ3)Cos[tβ2], E^(Iβ1 - I\β3)...
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### Using Dataset with TimeObjects in EventSeries

I'm new to Mathematica, and while this is potentially quite easy, I'm having difficulty using TimeObjects in the EventSeries ...
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### TimeSeriesAggregate—reformatting the date

Compute Aggregated Statistics for a Time Series The article linked to above provides a sample of aggregating time series data. ...
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### Read timeseries data from CSV

I am new to Mathematica and have v10. I would like to you use the new TimeSeriesAggregate[tsdata, "Quarter", Total] feature to return aggregated descriptive stats. I import a number of columns of ...
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### How to set proper time zone for weather data

I am running a query to pull historical temperature readings from Los Angeles using the following query: ...
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### Set hour of DateObject

Say I have a date object date = DateObject[{2016, 7, 17, 0, 0}], how do I later change the hour of that date object, without needing to know the value it currently ...
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### Throttle EventHandler KeyReleased

What might be the most elegant way to throttle the a,s functions triggered by an EventHandler...
132 views

### Predicting Manhattanhenge

At the time of writing, Manhattanhenge is tonight in New York City (ref 1), "an event during which the setting sun is aligned with the east–west streets of the main street grid of Manhattan, New York ...
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### How to convert output time in terms of seconds to minute with UnitConvert[]? [duplicate]

I have this code: AbsoluteTiming[g[x_, t_] := Sin[x]^90*(1 + t^2); Integrate[g[x, \[Tau]], {\[Tau], 0, t}]] with this output: I want to have convert unit to ...
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### How to specify RegularlySampledQ TimeSeries with EndOfMonth date unit MinimumTimeIncrement?

"EndOfMonth" is date unit that can be used with date functions. When specifying a TimeSeries object with date increments you ...
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### DateObject with DateFormat displays incorrectly in Dataset

DateObjects with DateFormat option appear to have the first date part truncated when displayed in a ...
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### Using DatePlus with a list of dates and list of times to add

I have a list of dates such as t2 = {"2016-06-08 05:00:00", "2016-06-08 05:00:00", "2016-06-08 05:00:01"} and a list of offsets (in seconds), such as ...
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### How to prevent TimeSeries adding TimeObject parameter and TimeZone option to DateObjects?

TimeSeries adds a TimeObject parameter and a TimeZone option to ...
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### Select Time Phase of Dataset with SQLDateTime Objects

I have a Dataset like this: ...
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### Getting AbsoluteTiming to display in hours, minutes, and seconds

I'm doing some extended length calculations and was wondering how I could get AbsoluteTiming to display in hours, minutes, and seconds. I googled and found nothing, ...
1k views

### Does Mathematica have a built-in date picker?

Does Mathematica have an interactive date input control that lets the user choose a date by browsing to a calendar view and returning the selected date as a date list? For example, something like the ...
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### Speed up AbsoluteTime with string input

I have millions of strings representing dates in the form: "05-Mar-2004 10:15:00". I would like to convert these to absolute times. For example: ...
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### Manipulate using DateObject

My question is about making a animiation using 'manipulate' using DateObject as parameter. I start with importing a file.txt, like: ...
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### FrameTicks and GridLines in DateListPlot

I would like to know what is the best way to configure one GridLine for the hour in LightGray and another for the days in ...
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### DatePlus and DayPlus perform much worse than my user-defined-function

I was debugging a function speed, and discovered that the time bottleneck was in DatePlus. I tried to change to DayPlus and get ...
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### How to override DisplayForm of (mixed) time Quantity

What's the best approach to overriding DisplayForm for specific types of Quantity eg time especially w/ mixed units? Current is ...
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### How to convert Dates with format 2016/03/1 to become {2016,3,1}

I have a problem to convert tide data with the form as follows. 2016/03/23,08:00,0.89,* 2016/03/23,09:00,1.41,* 2016/03/23,10:00,1.67,* 2016/03/23,11:00,1.44,* 2016/03/23,12:00,0.82,* 2016/03/23,13:...
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### overlap of data

I have two individual Date lists as Date Objects: List 1 = {1 Jan 1991 9 :00 , 3 Jan 1991 11:00 ..etc } List 2 ={ 7 Jan 1991 14:00, 9 Jan 1991 15:00 ..etc} For ...
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### The Orbit and Perigee of the Flamsteed comet

Historical context This year we have the 330-th anniversary of the Battle of Vienna - one of the great formative events of European history, it took place on September 12, 1683. Kara Mustafa, Grand ...
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### How to plot the hour of the sunsets

i have this code: ...
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### Matching timestamped data

I bet this question is a gimme for most of you guys, but I'm having a bit o' trouble figuring it out. Thanks ahead of time for your input and help. Soooo, I have two datasets where column 1 is a ...
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### How to skip weekends in DateListPlot?

How to skip weekends in DateListPlot, ie, drawing 20 something data points for a month and not leaving 2 days gap between weeks? Currently DateListPlot occupied the actual number of days for a month ...
382 views

### ScheduledTask with scoped variables. Working with timed evaluation

I guess I have to try harder and focus more but timed evaluation always frustrates me. I will show the issue on simple example of delayed trigger. ...
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### Combining first 5 columns from CSV file into AbsoluteTime date

Thanks in advance for all your help. I need to import data from a CSV file that looks like : (easier to read in excel) I would like to convert the data into timestamps by creating a Table with 2 ...
578 views

### From a list of dates, get a list of the last date available in each month

I wondered if anyone has another or even a more direct way of finding the last dates of each month available from a list of successive dates? I currently do the following (note: nothing special about ...
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### TimelinePlot - Handling dates prior to Year Zero

Interested in Using TimelinePlot to help me understand/remember important time periods in Earth prehistory and history. Following an a simple example in the Documentation I create a TimelinePlot for ...
1k views

### Is it possible to import dates and times directly as AbsoluteTime and by pass DateLists?

Date and time calculations are quite slow so I am exploring ways to minimize the number of calculations performed. As an example: ...
546 views

### Filter list based on date

What I would like to do is remove entries from a list of instrument data when it is in maintenance. The maintenance data I have is a series of dates which look like this; ...
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### How to get DateListPlot Epilog to display shapes

The following should produced a plot with an orange outlined disc labelled "A" on the dotted line. Epilog produces the dotted line and the text label but is unable ...
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### Automatic text-wrapping in labels in TimelinePlot

Part-related to this question and part-related to this one, I would like to make use of the new features of TimelinePlot in 10.3, but would like to incorporate some ...
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### Possible Bug with DateObject

So my questions is going to be hard to duplicate because I am not sure when or why it happens. I've read here several bugs with DateObject, but none of them ...
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### How to modify wrong time zone in a Date object?

How can one modify the wrong time zone in a DateObject, without a conversion? Can one manipulate the TimeZone directly without having the numerical value of the time changing?
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### working hours and negative time [closed]

I have a list of TimeObjects. I want to subtract 5h from each element and if TimeObject < 5h then give a negative hour. My ...
101 views

### How can DateObject handle calender weeks

I have dates given for a TimeLinePlot. These dates are in {year,week} format. DateObject ...
156 views

### Plot time along the y-axis?

How can I plot times along the Y-axis, (with dates along the X-axis) e.g. ...
44 views

### Date Conversion Using Regular Expressions on “Incomplete” Date Formats

I have a list of dates in one of the following formats: "1999/05/12", "1999/05/", "1999//", "****//**/", "" so that a list of such dates might appear as ...
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### Why do I get different results for the same input specified using natural language phrasing? [closed]

One of the comments to Stephen Wolfram's blog post on Ada Lovelace, mentioned that WolframAlpha (and verified in Mathematica as well) provided slightly different results for the question of Ada's age ...
250 views

### Behavior of TimelinePlot with multiple datasets of associations

Bug introduced in 10.1 and fixed in 10.3 The following TimelinePlot behaves as I would expect: ...
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### Finding the positions DateList dates in a range in large data set

There are similar questions to this like list search but this question is focused on finding at subset of dates in DateList format within a range of specified dates ...
429 views

### How much time should one give Mathematica for an integral evaluation?

Sometimes when I do integrals in Mathematica (M), it keeps thinking and thinking and I have no idea what is going on inside M. For how long should one wait or how does one know whether M has not got ...
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### Save a Mathematica notebook evaluated [duplicate]

My notebooks can take some time to evaluate and by quitting Mathematica, I have to reevaluate every definition I've made once I restart Mathematica. Is there a way to tell Mathematica to save the ...
184 views

### DateDifference isn't consistent when giving result in years

This isn't really causing me a problem at the moment, but it's weird. Is this documented anywhere? When I ask for the difference in days and then in years between April 1, 2015 and October 1, 2015 ...