Charts are not affected by any time change, i.e. the 9am hourly candle will always be there tagged 09:00.
The same for markets, their opening and closing will be shifted, as well.
It’s the code that will have to account for such time changes, such as DST, if they operate on markets which are non subject to change simultaneously. So when EU will enter DST the last Sunday of March, some countries (and markets thereof) may have already done it before, some may adopt it later and some will never make any change at all. If your code may be affected by those changes, then you will have to take it into account changing the code at the beginning of each year, when dates are already scheduled for changes.
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