I have dates in format yyyy-mm-dd. I am using XSLT 1.0. How we can find the difference between two dates .i.e number of days between the two entered dates.
Have tried using dayTimeDuration, days-from-duration. Nothing is working out. Also tried simply subtracting the dates using xs:date
Types and functions such as dayTimeDuration, days-from-duration require XSLT 2.0. Consider upgrading.
Alternatively, the EXSLT date-and-time library of extension functions (see exslt.org) might be available for your chosen processor.
Related
Discussing data time-formats, someone mentioned to me how he stores datetime (in a human-readable format) using floats as yyyymmdd.hhmmss, so 2019-09-18, 11:29:30am would become 20190918.112930
I'm trying to find out if this guy has invented his own format or if it is used (and described) elsewhere too - and if so, how is it even called...?
It’s probably homespun
I have seen a lot of date and time formats, and I have not seen this one before. My go is that his guy or his organization invented it themselves.
Edit: Thank you for confirming in the comment. Since comments are not always permanent on Stack Overflow, I quote here, you said:
Finally got confirmation from the source: it's homespun indeed.
As an aside I don’t like it. A float is stored in a binary format internally, and only after formatting it into decimal does it become human readable. Using a float for a “human readable” date and time was not what formatting of floating-point numbers was meant for, it’s a hack.
Use ISO 8601
For a human-readable format I recommend ISO 8601. Here 2019-09-18, 11:29:30am becomes 2019-09-18T11:29:30. Or even better and still within ISO 8601, convert to UTC and append a Z to denote UTC. So if your original time was in Europe/Berlin time zone, it would become 2019-09-18T09:29:30Z. As you can see, ISO 8601 is even more human readable than you friend’s format, and it is sortable as strings (as long as the years don’t go beyond 9999).
While he may have come up with it himself, it is also a formatting option in zipinfo.
The manual doesn't explicitly name it, but describes it as a sortable decimal format and decimal format.
Not sure if we are talking about SQL date format. If so, this date format is present in SQL Statements.
Not sure about the name, it's called in different ways: non-standard, ISO, Other format and so on.
Is present also in PHP.
According to Wikipedia, this would be similar to the ISO 8601, which permits, all of the following for date and time combined:
2019-09-18T09:18:26+00:00
2019-09-18T09:18:26Z
20190918T091826Z
except that the T to separate the time from the date is replaced by . and the time-zone information is dropped.
That specific format has limited popularity either in the yyyymmdd.HHMMSS or the C's strftime()-compatible %Y%m%d.%H%M%S form.
EDIT
As far as using float for date and time the way you suggests, it depends on the precision and machine representation.
If the system is following IEEE 754 basic standard (which is what most modern C compiler stick to), you would need at least float64.
However, it is not common to do so.
This might be in part because it may be difficult to correctly predict the accuracy of the time information, and it is not as bit-efficient as the Unix time.
Given that the only positive feature it has is that it can rely on standard %f from sprintf(), I would only see it advantageous when strftime() is not available or a performance bottleneck.
I have case classes that may be used for representing models that originate from either a database table or API object.
Should I use joda or java.util.date or java.sql.date or?
This is for a playframework app, and I will use these models to display the datetime on the UI side of things where I will convert the date to the current users timezone also.
I'm just really confused.
Agreeing with the Answer by mkurz…
java.time
Both java.util.Date and java.sql.Date, and their related classes, have been supplanted by the java.time framework built into Java 8 and later. See Oracle Tutorial. Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport and further adapted to Android in ThreeTenABP.
Search Stack Overflow to learn more (after reading the Oracle Tutorial linked above). Many examples and discussions have been posted.
Basic concepts
Date-time handling is surprisingly tricky. Leave your intuition at the door.
Strings are not date-time values; they are a representation of date-time values. Focus on using objects, not strings.
You may work with a date-only, a time-only, or a date-time.
Know that offset-from-UTC is just a number of hours/minutes/seconds while a time zone is a superset, adding rules for handling anomalies such as Daylight Saving Time (DST). Use OffsetDateTime for one, and ZonedDateTime for the other.
ISO 8601 standard provides sensible formats when parsing & generating Strings to represent date-time values.
The “Local…” types mean “no specific locality”. These have no meaning, are not points on the timeline, until you specify the context of a specific time zone.
The 3-4 letter abbreviations such as EST or IST you commonly see in the media are not time zones, are not standardized, and are not unique(!). Proper time zone names are continent/region.
Apply a time zone for presentation to the user, but most of your business logic, data storage, and data exchange should be in UTC (the Instant class).
Tips
While programming, forget about your own local time zone. Think in UTC.
Learn to read & write 24-hour clock times.
I would recommend http://www.joda.org/joda-time/quickstart.html
It works really nicely with play's json formatters and comes with a ton of helpers.
You are looking for java.time.ZonedDateTime which was introduced in Java 8 and should be used for representing date and time related information that have a timezone. You can save values like 2016-05-30T00:23:27.070Z with it. There is no need to use a third party library like joda time anymore (maybe in other cases there is, but not in your's)
(Do not use java.util.Date - most of it's methods are deprecated, for good reasons)
As a blogger saied:
「Scala does not have a datetime package, but we can use the ones provided by Java.
Java 8 provides a better data/time API, so 3rd-party libraries like Joda-Time is no longer required.」
Here is the blog:
https://www.hackingnote.com/en/scala/datetime
This will be helpful to you.
In official documentation I can't find any information how to write conditional statements for java.util.Date type fact fields in guided rules. For example how to compare such field to current date, check if it is equal omitting time, or check if it is date before some time from now?
Drools isn't a real-time program and it doesn't have an innate idea of Time or Now. If you need to investigate relations of some fact property w.r.t. some point of time X, you'll have to establish a fact carrying X as its data, and write your rules based on that.
A more or less coarse approximation of a fact representing Now can be made using timers. You can implement a rule that modifies a fact containing a value representing Time (e.g. java.util.Date) every second, or less frequently.
Blending out the time of the day is something you'll have to do using Java or DRL functions. Alternatively, if it is days you are interested in, use some custom class representing days, with some suitable day 1 defined by you.
you can give like
inputDate>=11-Nov-2014
provide your current date to inputDate rule input Fact variable.
I have to delete a few tests I create if the timestamp on these are older than a week.
On making a call to the API I get the created_at time stamps of all the tests in this format :
2014-08-04T04:49:28Z ,
2014-08-04T04:49:22Z ,
etc..
It looks like a DateTime object but is a String actually. So firstly is there a way to convert this to a DateTime object?
I need to compare these against the current time and date and check whether they are older than a week or not. For this I know there are several ways but I wanted to know which one is the shortest and most efficient in scala without importing any java utility. Though Joda would have been helpful but the API response gives me String
Thanks in advance!
Consider Scala wrappers for Joda (e.g GitHub /nscala-time
). It provides a rich API and avoids Java Date non thread-safety and mutability.
See What's the standard way to work with dates and times in Scala? Should I use Java types or there are native Scala alternatives? for further comments/discusison and usage examples.
What is the best way to transfer Dates and Times across. I am using GWT on the client/browser side and .NET C Sharp on the server and I am using JSON as data-interchange format. I am currently storing all the dates and times on the server as .NET DateTime. Now I have noticed, that if I use the GWT DatePicker or DateBox to pick a date and send it to the server as miliseconds (by doing date.getTime()) where the server takes this param as DateTime, I can see an hour offset due to the BST. I have situations where I have to have the date and time in separate boxes on the UI and the time setting along with the correct date is crucial because of scheduling.
The best way to interchange Date and Time values would be to serialize them into culture-independent, UTC based strings like: 2010-09-18T18:37:11. The problem is, Date and Time related operations tend to be implemented incorrectly...
As for your problem, I assume that it pops up during deserialization of JSON time, i.e. .Net treats this time as local (DateTimeKind.Local or DateTimeKind.Unspecified), thus converting it. Not sure how to deal with it, the brute force would be probably sending serialized string like above and deserializing manually like this:
DateTime date = DateTime.Parse(dateString, CultureInfo.InvariantCulture, DateTimeStyles.AssumeUniversal);
I'd recommend using standard such as ISO 8601 to transfer date time info in a string form. At my company, date time information encoded in JSON object is almost always in this format, e.g. "2015-10-12T18:41:11+01:00". This string can be parsed and understood correctly in all clients with different programming languages (Obj-C, Java, C/C++).