1. Local time zone (GMT offset or UTC to be perfectly accurate)
2. Daylight savings time (DST) to decipher the time + offset
3. Time zone of any meeting scheduled.
All three settings must be correct on both the meeting requester's computer and on each attendee's computer.
If one were going to travel to NY from Chicago and schedule a meeting for 8AM EST (NYC time) some day in the future the setting on the Chicago computer would be set to 7AM EST. On all recipient's computers with the TZ set to EST the time would display 8AM EST in the TZ EST calendars.
Outlook would reflect the current and accurate time for the EST attendees and all other TZ would still be accurate but be calculated +/- UTC based on their TZ setting.
This means, set the meeting up at 7AM CST, the current computer's TZ, in this case Chicago. Upon arrival in NY one could change the TZ to EST (I would not suggest this for day trips) and your schedule would advance or recede to meet the the TZ you are in.
For international travel it would be best to update the TZ for the duration of the trip.
Also, if your work includes two time zones this maybe very helpful tool for you:
Here are the steps to follow to include two time-zones in OUTLOOK
1.) Microsoft Outlook : click on Tools menu/Options.
2.) Click Calendar Options
3.) Click on Time Zone
4.) Check the Show an additional time zone check box
5.) Type a description of the second time zone
6.) Add the time-zone desired into the Time zone box
7.) To accommodate DST if and only if that TZ acknowledges DST, select the Adjust for dDST check box.