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Questions tagged [date-and-time]

Questions about Mathematica's date and time functions.

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50
votes
5answers
8k views

Mathematica command that allows it to read my intentions

In version 2.0 of Mathematica there was a command, ReadProgrammerIntentions[ ] which allowed it rapidly compose code that could solve problems simple to complex, ...
50
votes
1answer
3k views

How can I manipulate TemporalData?

Version 9 introduced TemporalData but, truth be told, the documentation doesn't suggest that one can do much with it. Many of us have probably assumed we'd be ...
36
votes
4answers
2k 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 ...
36
votes
2answers
3k views

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 ...
32
votes
1answer
884 views

What calendar is Mathematica using for dates in the distant past?

It appears that Mathematica treats all dates as proleptic Gregorian dates by default, a hypothesis that can be easily tested by using AbsoluteTime to compute the ...
26
votes
6answers
1k views

Faster alternatives for DayOfWeek

It has been noticed on several occasions that DayOfWeek function is rather slow when applied to a large list of dates, e.g. in this recent question. What faster ...
26
votes
3answers
5k views

how to make graphic timelines in mathematica

Hi does anyone know how to make timelines with mathematica? Something like that would be great!
24
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3answers
3k views

How can I make a heatmap of a days in year?

I know Mathematica has a ListPlot for time series but does it have a function for visualizing a list of dates as a heat map like this: This idea is from D3, check it out here.
22
votes
4answers
2k views

Are Easter days normally distributed?

How can Mathematica be used to check if Easter days are normally distributed? By definition, Easter day is the first Sunday after the first full moon after the spring equinox (so between March 23d ...
20
votes
11answers
4k views

Determining the week of a year from a given date

Consider the following: AbsoluteTime["17/04/2012",{"Day","/","Month","Year"}]; From my calendar in my office, I know that April 17th is in the 16th week of the ...
20
votes
4answers
561 views

Reproducing the XKCD “Consensus New Year” plot

This xkcd strip for December 31, 2018 had the following plot: How may I use CountryData with DateListPlot (or other related ...
16
votes
1answer
410 views

Is there a way to get AbsoluteTime to correctly report absolute time differences?

AbsoluteTime supposedly reports the "total number of seconds" between two dates, but it does not. For example, because of the leap second applied at 2012-06-30T23:...
15
votes
3answers
3k views

How do I compute sidereal time and JD?

There was once a package that provided a wide range of functions for computing astronomical information. This package now appears to be out of date; but as near as I can tell, many of the useful ...
15
votes
5answers
727 views

Does Mathematica support importing ISO 8601 date strings?

Does Mathematica have a built-in function to convert ISO 8601 formatted date strings (e.g. 2012-01-04T00:00:00) to a date list? ISO 8601 strings come in a variety ...
14
votes
4answers
381 views

How to evaluate the second argument of Cases only once

I'd like to find a fast but readable way to achieve the following: ...
14
votes
3answers
305 views

Min, Max are slow on TimeObjects

fixed in 10.1 (windows) There's something wrong with how Min and Max are implemented for ...
14
votes
2answers
1k views

UNIX time to DateList

I have data that is timestamped with UNIX time, which is the number of seconds since January 1, 1970 UTC. Unfortunately, it seems that most of the date and time functions in Mathematica are based on ...
14
votes
2answers
487 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. ...
13
votes
5answers
3k views

Sort date list in format DD/MM/YYYY

I have a list of dates (ranging from 2007 to 2012) in the DD/MM/YYYY format and I need to sort this list. My problem is, when I simply use Sort[] I get: ...
13
votes
4answers
2k views

Simpler way to fill date gaps with zero values

One basic problem when working with data like sales and dates is the case where you don't have sales in all days, so you have to fill it to take information as average or to make a plot. See this toy ...
13
votes
2answers
218 views

How do you import “ISODateTime” and capture the time zone?

Bug introduced in V10.4 or earlier and persisting through 12.0 (CASE:3920785) Back in version 10.2 or so, Mathematica began supporting the ISO 8601 date/time format, which is nice because it's used ...
13
votes
2answers
444 views

How is AstronomicalData interpreting its date arguments?

It is easy to confirm that the AstronomicalData is not interpreting its arguments as UTC (or "GMT", which is, in any case, ambiguous) dates by verifying that the ...
12
votes
1answer
413 views

TimeConstrained dynamic change of maximum time

I would like to run a time consuming function: TimeConstrained[f[x],maxseconds] and be able to change maxseconds during running (increasing or decreasing max ...
12
votes
1answer
778 views

How can I get the frame ticks from DateListPlot?

DateListPlot very nicely chooses major and minor frame tick and frame tick label/markers. I am building a custom graphics function where either the ...
11
votes
7answers
324 views

DateList coupled with String Operations

Through some webscraping, I have the following list: ...
11
votes
3answers
735 views

Does Mathematica have Month Range and Day range?

It is known that CharacterRange["a", "z"] gives list of characters from a to z. Does Mathematica have something similar for weekdays and months of the year? ...
11
votes
5answers
743 views

Calendar view outline

How to compute the outline of a calendar month like this D3 example. (D3 is a functional language built on JavaScript developed at Stanford and used by New York Times to deploy interactive graphics.)...
11
votes
3answers
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: ...
11
votes
1answer
408 views

Calculate moonrise

Mathematica has Sunrise[], but no Moonrise[]. But it has MoonPosition[], so I thought it ...
10
votes
3answers
403 views

How to work with Date calculations?

I have never worked using the DateObject function But I suspect there must be a (easy) way of doing it. I want to find out, when in the future, from which point, ...
10
votes
5answers
555 views

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, ...
10
votes
1answer
200 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 ...
10
votes
2answers
338 views

Approaches For Creating Cycle Plots in Mathematica

I am trying to create a cycle plot in Mathematica, and I am having a hard time finding the right approach to create the visualization. Can anyone give me a few pointers as to how to approach the ...
10
votes
3answers
1k views

MovingAverage[] and Fit[] with data containing DateLists

I have data which has the following appearance: data = {{DateList, Real}, ..., {DateList, Real}} It's easy to visualize the data by using ...
10
votes
2answers
935 views

interpolating function over dates

I've got a bunch of readings at various dates and times. I'd like to be able to interpolate and then integrate over, say days. I can do this by converting my date/time to ...
10
votes
1answer
995 views

How to import date (YYYY-MM-DD) data from a file?

I have a file with data in form {date, value}: 2010-05-19 17 2010-05-20 20 ...
10
votes
1answer
390 views

Plotting how sunrise times change over the year

I created a somewhat lengthy Python code to show how the time of sunrise varies over a year, resulting in the following figure (daylight savings were disregarded): The dataset can be found here. The ...
10
votes
1answer
204 views

Different behaviour of `DateRange` between 11.2 and 11.3

Bug introduced in 11.3 and fixed in 12.0. CASE:4028568 ...
10
votes
1answer
115 views

Dialog box that “times out” if the user doesn't respond

I want to ask the user (me) to make a binary choice, but also to give myself only 5 seconds in which to respond. In the absence of a response within 5 seconds, I want my code to close the dialog box ...
10
votes
1answer
328 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: ...
10
votes
1answer
147 views

DateList not using current year when a year is not specified

Bug introduced in 8.0 and fixed in 9.0 According to the documentation when using DateList but not giving it a year it should use the current year. It is not doing ...
10
votes
1answer
278 views

Why do DateList, DateString, and AstronomicalData ignore $TimeZone?

My reading of the documentation for DateList and DateString lead me to believe that both functions use ...
9
votes
5answers
489 views

Replicating a PlotStyle from Trees, Maps, and Theorems

How might I make a plot with this style, where the callouts are on the side and the y-axes chopped off for a minimal look? Here's some example data with the callout that I'd like to add, but I'm not ...
9
votes
2answers
875 views

How to count occurrences of Friday 13th

I would like to find a function that will count the number of times Friday 13th happens in a particular calendar year. Does anybody have any hints ? Thank you
9
votes
3answers
697 views

Timeline plotting: horizontal bars of time intervals

This text file logs the time that a process (identified by a number) changes state ("Brown", "Blue" etc.") ...
9
votes
3answers
543 views

Faster Alternatives to DateDifference

I need a faster implementation of FractionOfYear and FractionOfMonth, which do the following: Input: A time/date specified by <...
9
votes
1answer
136 views

Does Mathematica have a date region function together with operations like intersection?

Consider the following scenario. Suppose I consider time range from TimeObject[{18,30,0}] to TimeObject[{22,30,0}] on Weekdays ...
9
votes
1answer
678 views

Why does Mathematica's date for the battle Agincourt differ from the US Navy's?

If I ask Mathematica for the Julian Date for the battle of Agincourt with WolframAlpha["battle of agincourt date"] it reports ...
9
votes
1answer
325 views

How can I convert the dates returned by FinancialData into decimal representation?

I'm trying to run a regression using Fit on the output of FinancialData["SPY", "Jan. 1, 2011"]. However, the dates returned ...
9
votes
2answers
303 views

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 ...