On 03/12/2018 12:10 PM, Valery Ushakov wrote:
> -  else if (EQ (zone, Qt))
> +  else if (EQ (zone, Qt)
> +	   || (INTEGERP (zone) && XINT (zone) == 0))

Thanks for diagnosing the problem. If I understand things correctly, we 
can do a more-general fix, which should work for any used-in-practice 
time zone that is an integer hour offset from UTC. I installed the 
attached patch into master; please give it a try. I don't have easy 
access to NetBSD and would appreciate your testing it on NetBSD 6 and 7. 
I think this problem is limited to older NetBSD and so is not worth 
testing for in configure.ac (as 'configure' is pretty slow already).