The client Regional settings affect date and time interpretations within Dynamics NAV. The Region is easily set when using the Classic or Role Tailored Client (RTC). When using a Web Service its also easy, if you know how (like most things in life).

I have an application that takes Point-of-sale (POS) transactions from Advance Retail and passes them into Dynamics NAV. A problem arose where transactions for early one morning (say 6:00am 21^st Jan 2011) where appearing in NAV with a Posting Date of the day before (20^th Jan 2011). The problem was the client date time was based upon GMT +10 but the Web Service was working in UTC time.

The default Time Zone is UTC. -not very helpful when I live in Sydney Australia.

Settings within the client application making the Web Service call have no effect on the web service.

Within the CustomSettings.config file you'll find

In my case I want to use Australian Eastern Standard time.

Restart the web service and the Date and Time is now correctly interpreted.

Oh, and if you need the middle-tier (NST) to operate in different Time Zones, just run up another Web service. (see another post on how to do this)