Sounds reasonable, would be happy to merge.

Before merging the contribution, the one thing we need is a filled Contributor License Agreement (CLA), from https://github.com/FasterXML/jackson/blob/master/contributor-agreement.pdf
so if it would be possible to print it, fill & sign, scan and email to info at fasterxml dot com, that'd be great.

Looking forward to merging this fix.

Cool. Sent.

I will actually merge this to be included in 2.6.3 just because I haven't upgraded master yet -- so it will be included before 2.7. Just as an FYI; officially API shouldn't change in patch versions, but this is safe enough so as not to cause issues.

Would be great to also be able to do that with OffsetDateTime !

PRs welcome!

Yes. I'll see if I have time.
It should also be possible to easily format Instant. Then there could be a method in JavaTimeModule to set the format and timezone of all Instant based types at once.

@cbornet Actually there already is general-purpose support, as of 2.8:

JsonFormat.Value format = ....;
mapper.configOverride(Instance.class).setFormat(format);

as long as Instance (de)serializer accepts @JsonFormat information via createContextual().

Yes but you need to do this for Instant, ZonedDateTime, OffsetDateTime. It would be useful to have something like setInstantBasedTypeFormatter(DateTimeFormatter format). I don't think it can be done on the mapper since it belongs to the core so I'm wondering if it couldn't be done on the JavaTimeModule.

@cbornet It is a general facility to use and superior in that sense. But I could see benefit of having a helper method in JavaTimeModule that could act as shortcut like you suggest; method to call before registering.