If you do that then the data for 'now' will either be off the front of the chart or there will be a gap between the edge of the data and the right hand side of the chart.
Another solution if you don't want the whole machine running in UTC is to run a virtual machine configured for UTC and run the browser in that.
In theory we could add an option to display the timestamp in UTC. Would need some thinking about to make sure it doesn't interfere with other options, but could be done.
and for the link "change timezone of browser" that seems helpful
thank you so much for your help
(PS: i couldn't replay to your messages because of the limit number of message for the first day here, just wanted to say thank you ) )