Hi,

Thank you for your input on this!

The concern is that, in some cases, applications that parse the tzdata files were not expecting to find negative DST offsets (negative SAVE values in the data files) despite the fact that POSIX appears to support this.

As this is now the default format for tzdata, these applications should be fixed to recognize the negative DST offsets.

(NOTE: For f26, f27 and f28, we have provided the rearguard format to continue to support existing applications. This proposal announces the transition to vanguard format, allowing time to update applications in f29.)

On Wed, May 23, 2018 at 4:51 AM, Vít Ondruch <vondruch@redhat.com> wrote:

Is this going to be backward compatible or not? rubygem-tzinfo is using
tzdata as data source, so I wonder if any action is required.

Yes, it's backward compatible if your application recognizes that tzdata SAVE values/DST's can be negative.

Thanks,

Patsy