Originally Posted by AAaLot
My CC expires Nov 2005. I am in New Zealand.
If I attempt to use my CC at 8am on Dec 1, 2005 [i.e. 1:00pm on Nov 30 where the bank in at] will my credit card work or be declined?
Up front, I work in the technical end of the CC industry...
The POS device (credit card machine) you use will be set to local time and will validate the expiration date against it's own clock. At 8am local 12/1, your November expiring card has no chance. It will not be accepted by the device, if read using the magnetic stripe.
You'll have to do some serious persuading to have the retailer enter your card details with a different expiration date than what is printed on the card.
NZ is not a great example since it will expire your card in advance of you "NYC" bank by about 14 hours.
If you look at things the other way around, and attempt to get another 14 hours out your NZ card in NYC, things will be a little easier.
The local device will take your card because it's still 11/30 in NYC, even if it's 12/1 in NZ.
The main card schemes (Visa or MasterCard or ...) may choose to pick off the transaction as they send it to NZ and return it to NYC as being expired, but not always.
The transaction will arrive in NZ, where it's 12/1, and the card details in the message are officially expired.
Many card processing systems are aware of this and have a swap over period where both cards (old and new) are valid. Typically you will get your new card a few weeks before the old one expires, and you could start using it immediatly. Some systems will reject AMEX cards, which have start dates encoded on the magnetic strip, but other systems will allow you to use cards for a few days/weeks before the become actually valid.
It is most likely that the NZ card/transaction in NYC will be declined by the NZ bank as being expired.
It is most likely that the NYC card/transaction in NZ, if you can get it past the credit card machine, will be accepted by the NYC bank until 23:59 EST on 11/30.
Oh yes, as an experienced FT, you will have checked in advance that your cards are going to be valid during your trip, contracted your bank/issuer to make sure that any new cards arrive in time, and finally, mention to them that there may be unusual purchases from NZ for the period of your vacation so the fraud detection systems don't get too excited 
Regards,
Aidan
PS When training retailers I used to mention this type of scenario, and the staff were suggested to ask the cardholder if they also had their new card with them. In many cases they did!
Good question...