[jobigoud]

Your integer is wrong because it was computed by translating from the current offset of the timezone. What we are saying is that the timezone definition might change in the future (ex. Government no longer honor DST). At that point when you translate back your timestamp into local time it no longer matches the original schedule that the user set.

[gsich]

But the integer stays the same. That's the main point here. Everything else is just converting it to local time. Sure timezones might change that.