IHC dates are offset by one month

I have this odd issue where any DateTime items in OpenHAB gets the month offset by +1 if connected to an IHC date or time. For example I have these items:

DateTime ihc_last_restart_date	"Restart date [%1$tF]"	<info> {ihc="<0x12f8730e"}
DateTime ihc_last_restart_time	"Restart time [%1$tT]"	<info> {ihc="<0x12f8740d"}

They are updated fine, but month of both are offset when I check the item via e.g. the REST API.
Do anyone have an issue like this. I have looked at the conversion methods of the IHC date and time data types in the binding source. That seems to be fine. Odd thing is, even if it is an IHC time type converted to a DateTime, the month is still offset.
I am running on RPi OpenHAB 1.8.3.
Maybe @pauli_anttila have a clue?

Thanks and regards
Claus

@csk, I can agree that there is a problem with dates. I implemented date and time support, but never actually needed it by my self (most probably anyone else either, as this is not reported before). The root cause of the problem is that in Java months start from 0 (0=January) and in IHC months start from 1 (1=January). This is easy to fix, but I can’t promise when fix will be available.

OK, I also wondered why no one else had ever experienced this. I use it both for alarm logs and last controller reboot.
Should we make a bug issue about this on github? I guess the solution is simply to subtract one month from the source IHC date/time.
I have looked at the code. According to it, it also applies to the opposite direction OpenHAB->IHC. I dont see anywhere 1 added to the month. This I have seen used many places, but never any complain about an offset on month.
The strange thing is also that even it is only an IHC time I read out, the date is set to 1900/2/1, not 1900/1/1 as specified in the code.

I have created an issue on this in GitHub