Questions about Mathematica's date and time functions.

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4
votes
0answers
94 views

TimelinePlot with Interval in Associations

Bug introduced in 10.2 This is related to a previous question I asked about TimelinePlot and multiple associations (Behavior of TimelinePlot with multiple ...
0
votes
0answers
76 views

How to extract the time t of an interpolated function created by NDSolve? [duplicate]

I'm working with the function NDSolve. I give it the time of integration, the time I want it to evaluate my differential equations. Sometimes, it crashes before the end of its attribuated time ; For ...
2
votes
1answer
46 views

How to adjust the FrameTicks length in DateListPlot?

suppose I have the data for DateListPlot: ...
6
votes
4answers
324 views

How to combine Date and Time objects into DateTime object?

Considering a DateObject d and TimeObject t: ...
2
votes
1answer
191 views

How to make a cumulative time plot?

So I'm working with this data set where there is just one input(a date and time) per line in a .csv file. I've let Mathematica understand the input using "DateStringFormat". The time looks like Year-...
8
votes
2answers
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 ...
7
votes
3answers
237 views

Problem About TimelinePlot

Bug introduced in 10.1 and fixed in 10.3 TimeLinePlot was introduced in 10.1 I have some data from wikipedia. ...
2
votes
3answers
495 views

Converting timestamps into a decimal in minutes

I am importing a list of timestamps (hour:minutes:seconds) from a series of text files. I have the list: ...
5
votes
1answer
117 views

Handy dates conversion

I feel like something very basic is missing me, $dateformat = {"Year", "Month", "Day", "Hour"}; date = DateString[$dateformat] DateString["Date"] ...
0
votes
1answer
95 views

My simulation is not never finishing and it is taking so much time?

I am running simple code which involves calculation of two first order differential equations.It is taking so much time and i am unable to get the results as the simulation is never finishing. ...
4
votes
3answers
386 views

How could I transform the YYYYDDD date string/Integer to YYYYMMDD date string?

suppose I have lots of YYYYDDD date Integers which look like(for example): ...
5
votes
4answers
214 views

DateListPlot: Highs and Lows

I have this data: ...
5
votes
1answer
216 views

Problems with TimelinePlot

I'm trying to play with the example in this recent blog post, but I'm having a few basic issues with TimelinePlot: Labels are getting cut off: How can I get ...
5
votes
1answer
66 views

DateObject for current date skips a day when crossing the date line with TimeZone

The DateObject was introduced in version 10 of Mathematica. One can call it to fetch the current local date and time: ...
1
vote
1answer
118 views

How to convert absolute time to local time?

I tried this code: ...
8
votes
2answers
211 views

SetOptions for CoordinatesToolOptions for DateListPlot?

Bug introduced in 10.0 and persisting through 10.2.0 or later DateListPlot does not respect my Options setting for ...
1
vote
4answers
135 views

Mean duration between two specific data points

I have dataset such as: ...
2
votes
0answers
72 views

Why are the labels twitching vertically in TimelinePlot?

Why are labels jumping up and down here: ...
1
vote
1answer
77 views

Convert Dates to values on an X axis

I have a bunch of dates and values which I put into the DateListPlot to get a graph. However I would also like to put this information into the Fit or LeastSquares to estimate what the value would be ...
1
vote
3answers
190 views

How to calculate time period?

I have the starting and ending dates and times. And I need to calculate the night time in this period (from 10 pm (22) to 6 am (6)). Example: starting date and time is {2015, 1, 4, 3, 10} ending date ...
1
vote
0answers
94 views

Improving semantic interpretation of dates

SemanticInterpretation and Interpreter are promising but imperfect, eg extracting dates and calendar expressions from semi-...
10
votes
1answer
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: ...
5
votes
1answer
127 views

How to remove the TimeZone from a TimeObject

TimeObject constructor adds TimeZone even when it's not meaningful or appropriate. In this example, Mathematica imputes ...
4
votes
2answers
113 views

Make a time IntervalSlider

I want to make a time interval slider with an initial setting of (10:00:00 Mar. 8 2015, 12:30:00 Mar. 8 2015) and which varies from 00:00:00 Mar. 8 2015 to 22:30:00 Mar. 8 2015 with a granularity of ...
4
votes
2answers
2k views

No weekends please

I need to get the DateValues of the last 30 days (starting from yesterday, not today!) excluding saturdays and sundays. I want that the dates are german time (GMT +...
4
votes
1answer
139 views

How to restart a Clock

The code below is to demonstrate color afterimages. The user chooses a color, fixates the changing number at the center until it reach 30 (seconds), then manually switches to white to observer the ...
2
votes
1answer
68 views

DateValue returns inconsistent types

More of a 'why' than a 'how' question... DateValue[{2014,4,12},"DayName"] returns Saturday, a symbol rather than the string "Saturday". Every other result that ...
1
vote
0answers
56 views

DateObject from AbsoluteTime broken

In the middle of a session (10.0.2 / Win64 / 2.7Gb working set - peak was over 7Gb) the form/definition for DateObject from an integer has disappeared. ...
8
votes
1answer
94 views

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 ...
1
vote
1answer
52 views

How to change time zone for all outputs? [closed]

How to change the time zone in Mathematica for all functions returning a date or time?
1
vote
1answer
52 views

Change date format in nested lists

I have a list of index symbols and data as follows: ...
3
votes
3answers
209 views

Delete rows based on specific periods

I have data (.xlsx format): two columns - data in first column imported as DateObject (dates with specific time), data in second column are numbers (113388.28, 865165.98 etc.). I want to delete the "...
5
votes
3answers
291 views

Converting between AbsoluteTime and Unix time

By trial and error, I've found that the following gives the current Unix time: AbsoluteTime[] - UPOCH where UPOCH can be defined in any of the following ways: <...
3
votes
2answers
149 views

AbsoluteTime parse two different date formats

I have a series of dates that regularly change format (24 hrs/12 hrs). Is there an easy way to parse this data? ...
5
votes
2answers
264 views

Time Zone Conversion

I use Mathematica to administer my share depots. The depots contain shares of many different time zones. I update the depot values several times a day. My problem is that Sidney, Australia, (it might ...
0
votes
0answers
200 views

NDSolve: basic settings for PDEs

I am trying to learn how to solve PDEs in Mathematica in order to deal with relatively simple problems without needing to formulate weak formulations in FreeFem++, which is rather time consuming for ...
1
vote
1answer
178 views

How to plot multiple yearly data in one graph

There is a dataset: for each year a single data for 6 seas. I would like to have a graph to visualize paralel changes. This is what I attempted to reproduce http://www.eea.europa.eu/data-and-maps/...
1
vote
0answers
64 views

Is Daylight Savings Time accounted for when using AbsoluteTime[]? [closed]

I have been running rather long computations lately and timing them using AbsoluteTime[] by calling it at the start and end of the computation. ...
14
votes
3answers
286 views

Min, Max are slow on TimeObjects

fixed in 10.1 (windows) There's something wrong with how Min and Max are implemented for ...
1
vote
0answers
38 views

Expose TimeObject fractions of a second and user-defined formatting

The default TimeObject formats (doc page), don't display fractions of seconds: ...
6
votes
3answers
159 views

EasterSunday replacement in Mathematica 10

The Calendar package, now obsolete, had functionality for "special dates", in particular EasterSunday[]. The documentation says it's been subsumed into Wolfram ...
1
vote
1answer
80 views

How to convert a string representing date into a DateList expression?

How to convert a string representing date into a DateList expression? For example, how to turn "1/2/2000" into {2000,1,2} assuming American style, and {2000, 2, 1} assuming European style, ...
4
votes
0answers
138 views

Is it possible to specify GMT as default in OpenSQLConnection or JDBC?

I'm connecting to a PostgreSQL database, with tables containing TIMESTAMPs with timezone, using ...
3
votes
0answers
71 views

How can I set up a cell style that is ascending dates? [closed]

Outline style notebooks have cell counters that are simply ascending numbers, but what if I want to apply a function to them and have descending dates like this: So that they auto format and the ...
1
vote
2answers
277 views

How do I remove the quotation marks from each element of a list containing dates that I have import from excel?

I've been stuck in this problem for 1 week. I just want to make a graph (Log-Return vs time (in year, month, day)). The code is: ...
3
votes
3answers
160 views

Get the complement date range

Suppose that I have a date range list drlist = {{"2015-01-01", "2015-01-05"}, {"2015-01-07", "2015-01-07"}, {"2015-01-12", "2015-01-23"}} ...
1
vote
1answer
79 views

Why does TimeSeriesShift is just adding a fixed number of days?

I'd like to shift all contents of a TimeSeries object by one month. By shifting Feb. 1st I would expect to receive Mar. 1st. However it's not the case for Mathematica: ...
4
votes
4answers
244 views

Extract Specific Dates from DateList

Hopefully this is an easy question but I couldn't find an easy answer anyway. Surely there is some simple way to splice this... I want to take a large datelist in the format of {{2014,12,31}, value} ...
1
vote
1answer
184 views

Trace two DateListPlots?

I currently have two DateListPlots in the same graph, with two different y-axes. I downloaded the package "TwoAxisDateListPlot" to accomplish this with ease. Now I want to be able to trace both of the ...
1
vote
1answer
167 views

Plotting CSV files with UTC Universal Time

So I have many CSV files in format like this: 2014-12-11T16:13:13.038337Z , 3.90092 2014-12-11T16:14:13.456558Z , 3.89734 2014-12-11T16:15:12.444318Z , 3.90092 I imported a CSV file ...