Thanks for all the replies it has helped a lot.

Would it be worth storing both local date/time with offset from UTC and UTC date/time?

E.g.

TransactionID ...

I understand the difference between language and timezone, I was just giving some background to the application. The application will be storing details of customer transactions from different countries...

The application needs to support multiple languages and therefore timezones. So the application will take care of displaying date/time in the correct format based on locale.

However, I'm not sure...