How do I change the timezone of the X axis on an existing plot?

Suppose I have a figure with one or more line objects, e.g.

T = datetime(2018,1,1,0,0,0,'TimeZone','UTC')+minutes([0:9]);
y1 = 1:10;
y2 = 10:-1:1;
figure; 
plot(T,y1); 
hold all; 
plot(T,y2);

Now I want the X axis to display in a different timezone, e.g. 'Asia/Taipei'. I've tried modifying the x limits, the x tick values, the properties in the date-time ruler, the individual XData in the line objects, and making changes after turning off visibility of the XAxis and Line objects. Each time I change the time zone in one of these object properties, the zone is automatically reverted to UTC. Is there anything I can do short of copying the data out of my original figure and re-plotting new data in an updated time-zone?

[dpb]

I confirm the behavior here (R2017b); looks like a bug to me; seems as though the axis ought to reflect the date/time including timezone of the underlying data, agreed.

I'd report it as a bug; see the "contact us" link at top of page or email <mailto:[e-mail] [e-mail]>; attach link to the Q? here.

Answer 1

[Benjamin Kraus]

Starting in MATLAB R2023a, you can now update the time zone of the x-axis on existing plots by setting the ReferenceDate on the ruler.

You can read about this on the DatetimeRuler Properties doc page.

T = datetime(2018,1,1,0,0,0,'TimeZone','UTC')+minutes([0:9]);
y1 = 1:10;
y2 = 10:-1:1;
figure; 
plot(T,y1); 
hold all; 
plot(T,y2);
ax = gca;
ax.XAxis.ReferenceDate = datetime(2018,1,1,0,0,0,'TimeZone','Asia/Taipei');