Like Kobra, I am interested to know just why a timezone influences shipping charges.
But let's assume that in your case it does.
You can indeed set up "time" zones - even though zencart will not see this as having anything to do with time itself.
It is a little tricky - because some states have more than one time-zone, so in your STATES field in the database, you are going to have to split up certain states to match the split in time zoning.
In the database, you have one state called Arizona, but if you want to invoke time zone differentials, then you will need to ADD a "state" called Arizona Navajo - because Arizona Najavo has a different time zone than the rest of Arizona.
Use the table below to see what states need "splitting". Then create your new "split" states in the database.
So, you have the following "states" with their GMT differences. The GMT differences and be translated into the time zones commonly used (Eastern, Central, Mountain, Pacific, Alaska, Hawaii)
State Standard Time Daylight-Saving
Time
Alabama GMT-6 GMT-5
Alaska## GMT-9 GMT-8
Alaska (Aleutian Islands) GMT-10 NA
Arizona## GMT-7 NA
Arizona (Navajo) GMT-7 GMT-6
Arkansas GMT-6 GMT-5
California GMT-8 GMT-7
Colorado GMT-7 GMT-6
Connecticut GMT-5 GMT-4
District of Columbia GMT-5 GMT-4
Delaware GMT-5 GMT-4
Florida GMT-5 GMT-4
Florida (W) GMT-6 GMT-5
Georgia GMT-5 GMT-4
Hawaii GMT-10 NA
Idaho (N) GMT-8 GMT-7
Idaho (S) GMT-7 GMT-6
Illinois GMT-6 GMT-5
Indiana GMT-5 GMT-4
Indiana (NW) GMT-6 GMT-5
Iowa GMT-6 GMT-5
Kansas GMT-6 GMT-5
Kansas (W) GMT-7 GMT-6
Kentucky (E) GMT-5 GMT-4
Kentucky (W) GMT-6 GMT-5
Louisiana GMT-6 GMT-5
Maine GMT-5 GMT-4
Maryland GMT-5 GMT-4
Massachusetts GMT-5 GMT-4
Michigan GMT-5 GMT-4
Michigan (W) GMT-6 GMT-5
Minnesota GMT-6 GMT-5
Mississippi GMT-6 GMT-5
Missouri GMT-6 GMT-5
Montana GMT-7 GMT-6
Nebraska GMT-6 GMT-5
Nebraska (W) GMT-7 GMT-6
Nevada GMT-8 GMT-7
New Hampshire GMT-5 GMT-4
New Jersey GMT-5 GMT-4
New Mexico GMT-7 GMT-6
New York GMT-5 GMT-4
North Carolina GMT-5 GMT-4
North Dakota GMT-6 GMT-5
North Dakota (W) GMT-7 GMT-6
Ohio GMT-5 GMT-4
Oklahoma GMT-6 GMT-5
Oregon GMT-8 GMT-7
Oregon (E) GMT-7 GMT-6
Pennsylvania GMT-5 GMT-4
Rhode Island GMT-5 GMT-4
South Carolina GMT-5 GMT-4
South Dakota (E) GMT-6 GMT-5
South Dakota (W) GMT-7 GMT-6
Tennessee (E) GMT-5 GMT-4
Tennessee (W) GMT-6 GMT-5
Texas GMT-6 GMT-5
Texas (W) GMT-7 GMT-6
Utah GMT-7 GMT-6
Vermont GMT-5 GMT-4
Virginia GMT-5 GMT-4
Washington GMT-8 GMT-7
West Virginia GMT-5 GMT-4
Wisconsin GMT-6 GMT-5
Wyoming GMT-7 GMT-6
Then... in ZENCART... create ZONE DEFINITIONS named as each time zone, and then assign the relevant states to each of those definitions.
You will then have a zone called Eastern Time, which will contain all the states (and split states) that fall into that zone....
Etc...
