How to convert UTC to Australian Eastern Daylight Time (AEDT)? [duplicate]

Question

We are downloading data from our trading partner's API. Till now we were working with "E. Australia Standard Time" and it was working fine.

After daylight saving started our trading partner said that they are working with "Australian Eastern Daylight Time (AEDT)".

I have used following code to convert from UTC to "E. Australia Standard Time".

DateTime utcTime = DateTime.UtcNow;
TimeZoneInfo objTimeZoneInfo = TimeZoneInfo.FindSystemTimeZoneById("E. Australia Standard Time");
DateTime TPDateTime = TimeZoneInfo.ConvertTimeFromUtc(utcTime, objTimeZoneInfo);

But I am getting following errors when I use "E. Australia Daylight Time" or "Australian Eastern Daylight Time (AEDT)"

The time zone ID 'E. Australia Daylight Time' was not found on the local computer.
The time zone ID 'Australian Eastern Daylight Time (AEDT)' was not found on the local computer.

What timezone id should I pass to FindSystemTimeZoneById() method to convert correctly to Australian Eastern Daylight Time (AEDT)?

Answer 1

You probably want to use "AUS Eastern Standard Time" (for Canberra, Hobart, Melbourne and Sydney). Despite having the word "Standard" in the name, this accounts for daylight savings time and uses UTC+10 in winter and UTC+11 in summer:

var tz = TimeZoneInfo.FindSystemTimeZoneById("AUS Eastern Standard Time");

TimeZoneInfo.ConvertTimeFromUtc(new DateTime(2018,1,1,0,0,0,DateTimeKind.Utc), tz); 
    // => 01/01/2018 11:00:00
TimeZoneInfo.ConvertTimeFromUtc(new DateTime(2018,7,1,0,0,0,DateTimeKind.Utc), tz); 
    // => 01/07/2018 10:00:00

The "E. Australia Standard Time" time zone is for Brisbane, where they do not observe daylight savings time.

You can get a complete list of available time zones using the TimeZoneInfo.GetSystemTimeZones() method, or by running tzutil /l at the command line.