I am consuming the international weather forecasts via Wunderground's XML API:
http://wiki.wunderground.com/index.php/API_-_XML
Looking at an output for Kabul, Afghanistan for instance:
http://api.wunderground.com/auto/wui/geo/ForecastXML/index.xml?query=OAKB
I notice that there is no UTC offset. The closest that I can see is this:
<tz_short>AFT</tz_short>
Which identifies the current TimeZone is AFT. The problem I see is that there is no universally accepted time zone abbreviations, so I cannot take these abbreviations and look up and offset from C#'s TimeZoneInfo objects.
Is there a listing of Wunderground's Time Zones abbreviations/names/offsets so I can map their Time Zones to the TimeZoneInfo objects, or is there a better way to get this information? I will need to use the TimeZoneInfo so I can calculate daylight savings time for different locations internationally.
Here is an idea of what you can do to acquire a UTC offset.
Use the epoch field from the XML output, which will be in UNIX time (number of seconds since 1970-01-01 00:00). This time will be in UTC/GMT. Then, either by converting the contents of the pretty field, or by using the day/month/year/hour/minute/second fields, determine the difference between the published local time and the epoch time. This will give you your UTC offset. There is also a isdst field to tell you whether or not the zone is honoring DST at the moment.
Unfortunately I don't know of a comprehensive list of time zone abbreviations, so using the method above to determine the offset and DST is probably your best option. Good luck!