Questions about Mathematica's date and time functions.

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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
104 views

How to convert absolute time to local time?

I tried this code: ...
8
votes
2answers
194 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
131 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
72 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
180 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
88 views

Improving semantic interpretation of dates

SemanticInterpretation and Interpreter are promising but imperfect, eg extracting dates and calendar expressions from ...
10
votes
1answer
241 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
112 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
100 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
130 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
63 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
52 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
91 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
50 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
51 views

Change date format in nested lists

I have a list of index symbols and data as follows: ...
3
votes
3answers
206 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
266 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
136 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
255 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
142 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
161 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 ...
1
vote
0answers
59 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
282 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
153 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
67 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
134 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
70 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
244 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
153 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
75 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
237 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
178 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
154 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 ...
2
votes
4answers
289 views

How to remove hours, minutes, seconds from list

How to remove 0 that represent hours, minutes, and seconds from a date list say a ...
5
votes
1answer
102 views

ChineseLunar calendar system mystery

I tried to make a custom holiday calendar for the Korean Stock Exchange. And I found that the built-in "ChineseLunar" calendar system gives me an awkward result. The code is ...
1
vote
1answer
53 views

DateListLogLogPlot

The command completion feature in Version 10.0.1.0 shows a command DateListLogLog but there is no documentation and doesn't work. Is this something that is going to be released in the near future and ...
4
votes
2answers
361 views

Should we invest in Apple?

Ticker[comp_String] := Interpreter["Company"][comp] /. Entity[_, x_] :> x ticks = Ticker /@ {"Apple", "Google"} {"NASDAQ:AAPL", "NASDAQ:GOOGL"} ...
1
vote
1answer
102 views

Manipulate using DateObject

My question is about making a animiation using 'manipulate' using DateObject as parameter. I start with importing a file.txt, like: ...
1
vote
1answer
66 views

DayRound Rounding Values:No difference between “Preceding” and “Following”?

On Mathematica 10.0.1 both DayRound[{1980, 2, 29}, "EndOfMonth", "Preceding"] and ...
4
votes
2answers
127 views

How to sum values in the list that belongs to same week

I need to sum values that belongs to same week. For example, I have the list x with one column and n rows. Format: ...
5
votes
1answer
84 views

“ComputedDate”'s interpretation of “next”

Today Interpreter["ComputedDate"] /@ {"next Monday", "next Tuesday", "next Wednesday"} What explains this behavior? Can ...
1
vote
0answers
120 views

How to create a complex variable from dated list values

Can anyone help me to construct a variable "PI" from values of variable x. Variable x represents a group of two time series rj and ri on equal dates(joined two dated lists with states).Variable x have ...
6
votes
2answers
146 views

How to speed up Min of DateObjects?

I'm in version 10.0.1 using a Dataset to do some plots and things. For one of the plots I need to get the minimum date of a some filtered set of the ...
2
votes
1answer
177 views

A possible bug with regard to DateObjects in Version 10?

Bug introduced in 10.0 and fixed in 10.1 Bug related to the Suggestion Bar Bug While getting used to the new data type Date Object in Version 10 I noted that ...
1
vote
2answers
133 views

How to select states with equal times

Can anyone show me how to select the states that have equal times-dates. For example, i have two time series. First that have 10 observations, say from 2014/10/1 to 2014/10/10, and second that have 7 ...
6
votes
4answers
680 views

Change string date/time to be understandable for mathematica

I'm trying to convert a string of a data and time to be understandable for mathematica (I want to make time related plots). However, I can get my head around how to do this. For example: ...