The client wants to see windows timezones, the ones at Time column here https://support.microsoft.com/en-us/help/973627/microsoft-time-zone-index-values except with UTC instead of GMT.
And also wants to see abbreviations. But I can't find any official windows timezones abbreviation list. What I find is IANA abbreviations.
We are goin to convert windows timezones to IANA timezones to work with time.
But the question is does IANA abbreviations=Windows timezones abbreviations? If not where can I find the list of the rule for the windows abbreviations?
A few things:
The list you pointed at is not the official list of Microsoft Windows time zones. It is a copy of a very old static list from Windows Embedded 1.1., which has long been deprecated. There presently is no actively maintained list of all Windows time zones on a Microsoft web page.
To get a list of Windows time zones, call TZUTIL /L on the command line. It will return the ID and display name of each time zone installed on the system.
If you look at the CLDR zone mapping file, you'll see that many Windows zones map to more than one IANA zone. If you simply map the Windows zone to the 001 "golden zone", you may end up picking an IANA abbreviation that doesn't apply for the user. Thus, if you take the approach you described (converting to IANA and taking the IANA abbreviation), be sure to take the country code into consideration as well when doing the mapping.
Also:
There is no official single list of time zone abbreviations anywhere, because time zone abbreviations are not standardized. Many of the abbreviations we might use in English don't necessarily apply to non-English speakers, and many time zones don't have abbreviations at all.
Even in English, many time zone abbreviations are contradictory or ambiguous.
Some examples of problematic time zone abbreviations:
CST mean Central Standard Time, Cuba Standard Time, or China Standard Time?IST mean India Standard Time, Israel Standard Time, or Ireland Standard Time?HST or HAST?HNE (Heure Normale de l'Est) be used instead of EST (Eastern Standard Time) in Quebec, Canada since its official language is French?MSK, but that's offensive to some because that abbreviation is also commonly used for Moscow, Russia. Belarus has one time zone for the whole country, and they don't speak English there. IANA gives the abbreviation as simply the numeric UTC offset +03 (since mid 2011).Because of the above problems...
There is no official list of time zone abbreviations for Windows time zones. Windows doesn't use them.
You might find some time zone abbreviations listed in CLDR data, and exposed with various libraries and APIs, but they only sparsely populated in the data set. CLDR has not been reliably collecting or maintaining time zone abbreviations.