Joda time interval local dating

Joda-Time - Java date and time API - Download and Installation

But there is a difference in them believing those falsehoods, and simply not . Obviously you can expand this to include local time, we haven't in order to .. For calculations of dates and times, it is very useful to have a notion of time intervals, .. Joda Time was "adopted" as a part of java 8 on the You should spend some time (no pun intended) to grasp the Jodatime concepts ( eg) if you need to do time calculations involving different timezones. To use Joda-Time you need to download the latest version. The download will contain the joda-time jar file. Once you add this to your classpath you will be able .

Java has default classes to represent Types 1 and 3, but is missing a simple class for Type 2. So I designed one myself: For events in the past, a timestamp 2. A partial representation of date, to denote repeating events or events which last a whole day.

  • System time

The partial representation should optionally include a timezone. This allows me to say: For calculations of dates and times, it is very useful to have a notion of time intervals, durations of time and weekdays. Can you give an example where that would be used?

jodatime - Joda Time Interval between two dates including time zone - Stack Overflow

I'm thinking of a user who wants to be woken up at 7am even if they change their timezone. But that wouldn't require millisecond precision. Couldn't you do that with the first two types I mentioned? With two instances of Type 1 it's trivial to count the number of milliseconds between them. With two instances of Type 2 you can have d1. Is that common enough and complicated enough to warrant an extra type? When I write code to process credit card payments, I just record the card expiry as two integers: When I want to check if the card is expired I just create a Type 2 instance representing the last day of the month.

Seems to me I could do something similar for 'repeat on 5 May'. That may seem like a special case, but it is relatively common, it might also matter for normal business meetings in a foreign country - UK time is an hour behind France, so if you are a UK business man trying to have a meeting in Paris, you need to take time zones into account. It is never trivial to calculate the duration between two times, because you may have to take into account leap years, leap seconds, months that does not have the same number of days, etc, not to mention if they are in two different timezones.

Joda Time and a Brief History of the World

That doesn't mean it isn't possible, but it is not trivial. What is the last day of the month? That depends on the month, and if that is February it also depends on the current year. If you need to process credit cards, you might need to know the last banking day of the month, which could be quite early during e.

BTW to know when easter falls, your dating system needs to know about the lunar calendar. This doesn't even begin to touch what happens in countries that celebrate Ramadahn. This puts the burden on developers to use them in a thread-safe manner and to think about concurrency problems in their day-to-day development of date-handling code.

The new API avoids this issue by ensuring that all its core classes are immutable and represent well-defined values. The new API models its domain very precisely with classes that represent different use cases for Date and Time closely. This differs from previous Java libraries that were quite poor in that regard. Date represents an instant on the timeline—a wrapper around the number of milli-seconds since the UNIX epoch—but if you call toStringthe result suggests that it has a time zone, causing confusion among developers.

It does so without imposing additional burden on the majority of developers, who need to work only with the standard chronology. They are local in the sense that they represent date and time from the context of the observer, such as a calendar on a desk or a clock on your wall.

A desktop JavaFX application might be one of those times. These classes can even be used for representing time on a distributed system that has consistent time zones.

When constructing a value by its constituent fields, the factory is called of; when converting from another type, the factory is called from. There are also parse methods that take strings as parameters. Because all core classes are immutable in the new API, these methods are called with and return new objects, rather than using setters see Listing 3.

There are also methods for calculations based on the different fields. You can either write a WithAdjuster, which is used to set one or more fields, or a PlusAdjuster, which is used to add or subtract some fields. Value classes can also act as adjusters, in which case they update the values of the fields they represent. Built-in adjusters are defined by the new API, but you can write your own adjusters if you have specific business logic that you wish to reuse.

The truncatedTo method exists to support such use cases, and it allows you to truncate a value to a field, as shown in Listing 5. A time zone is a set of rules, corresponding to a region in which the standard time is the same.

There are about 40 of them. They move roughly in sync, but by a specified difference.