I came across https://blog.joda.org/2009/11/why-jsr-310-isn-joda-time_4941.html.
1) I am currently migrating Java Calendar to joda-time. I was wondering, should I use threeten instead of joda-time? Is threeten production ready?
2) Can threeten library and joda-time libraries exist together in a same application? As I am using some 3rd parties libraries, which is using joda-time library too.
3) Will joda-time become an abandon project since there is threeten?
Official reply:
As of January 2011, ThreeTen is still what I'd classify as an Alpha. That means that I am changing method names, classes appear and disappear etc. That said, the code that is there is basically sound and tells the right time.
As such, I currently advise projects to use Joda-Time until ThreeTen enters Beta, which will be this year (2011) at some point.
It is possible to have both Joda-Time and ThreeTen in the same application. When ThreeTen is stable I intend to add the interfaces from ThreeTen to Joda-Time providing interoperability. However, interoperability will never be easy as the classes have the same names.
Joda-Time will continue to be released for a good period after ThreeTen is complete. But there will be a push to move to ThreeTen if JSR-310 completes such that it is in Java SE 8.
Update, March 2014,
As of 2014-03-05, JSR-310 was approved for inclusion in Java JDK 8. For more information, see the ThreeTen home page.
This is just a suggestion what I would do.
Since Joda-time is heavily tested by lots of users and they still recommend it, that means it's a good library. JSR-310 -- I haven't seen this before this post of yours. Also, I am not sure how many people are using it -- or if it's completely bug free. May be it solves the Joda-time issues mentioned in the link that you have posted, but what guarantees that it is not having a newer bug.
That said, I will wait for JSR-310 to mature and be popular. And probably use in some of the non-critical projects. And, probably, eventually accept it as the blogger says, "(JSR-310 is) an API 'inspired by Joda-Time'" . In the mean time, I will use Joda-time.
Looking around the stuffs regarding it, I found this: http://sourceforge.net/apps/mediawiki/threeten/index.php?title=ThreeTen
It quotes:
The ThreeTen project is still in Alpha so methods may appear and disappear at any point. (Status - December 2010)
I WOULD RECOMMEND TO NOT TO USE IT RIGHT AWAY
The main concern about Joda-Time is doesn't support Um Qura Calendar , it's support Kuwaiti Calendar
来源：https://stackoverflow.com/questions/4622918/should-i-use-threeten-instead-of-joda-time