Comment 2 for bug 1674195

bzr log --timezone local

The calculation of the localtime use datetime.fromtimestamp() and datetime.utcfromtimestamp() that are as buggy on Windows with negative timestamp as on 32-bit platforms with timestamp outside of the 32-bit range.

Fixed this by switching to 'original' timezone if 'local' is buggy (anyway it's only a showing log option,so not really important, but should never fail).