Determine UTC Offset for a given Time Zone?

I am using an API to bring data into Matlab, and the timestamps are in UNIX time format. It also returns the local time zone for the data. UNIX time is based on UTC, so it convert it into a usable timestamp, I need to consider the UTC offset for the given time zone. The problem is, I can't seem to find a way to input a time zone to Matlab and have it output a UTC offset. I know that this information is available, because you can use tzoffset. But that requires a datetime input. Which puts me into a kind of catch-22. In order to convert to a datetime, I need the UTC offset. But to get the UTC offset, I need a datetime.

Is there any function that will tell me the UTC offset if I give it a timezone?

[James Tursa]

How do you have the time zone information? As a string of some sort that you need interpreted?

Answer 1

[Peter Perkins]

All you need to do is:

>> datetime(1490742843,'ConvertFrom','posixtime','TimeZone','Europe/Paris')
ans = 
  datetime
   29-Mar-2017 01:14:03

You don't say what form your time zone info is in, but datetime is pretty forgiving. See the doc for datetime.TimeZone.

[peaksix]

Thanks, this worked perfectly.

Answer 2

[Jerome Blaha]

Two methods that I love:

One is a call to Java directly (credit to someone else here who found the solution)

You can also set the java to different time zone inputs (Google is your friend)

java_time=java.util.Date('Thu Mar 05 09:57:01 PDT 2023');   % Alternate for PDT zone date time input
java_time=java.util.Date();                                 % Uses the current local date and time,
utc_offset=-java_time.getTimezoneOffset()/60;           %UTC offset from local time zone, only verified in Matlab R2015b

utc_offset =

    -7

Or you can use datetime:

t1 = datetime(datestr(now),'TimeZone','local');  % can change local to whatever timezone interests you
dt=hours(tzoffset(t1));  % As a bonus, daylight savings time offset of 0 or 1 is also returned if you use [dt,dst]= (tzoffset(t1));

dt =

    -7