@Beatrix W The code from Greg shows the new framework in all it's awful glory. When do I care about timezones? Very seldom.
But you should care about timezones. That's the whole point. The simplicity of the old date class comes with the problem of making it look like it does things right across time and timezones when it really doesn't. The reason I included all of that timezone stuff was that I didn't know what the timezone of the original date was. If it had been Zimbabwe, the TZ offset would have been very significant to the user.
Ever try to get the # of seconds between two dates when one is before daylight savings time and one is after? The timezone where you do that calculation matters.
Did you know that Timezones change from time to time? Or that parts of Indiana and Arizona don't observe daylight savings time at all? What does your app do if a user moves in or out of those areas (lives in New Mexico and works in Arizona). Does it handle that properly?