Calendar heatmap dates shifted by one (converting to local time zone)

[hyperborea]

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• I have checked the superset logs for python stacktraces and included it here as text if there are any.
• I have reproduced the issue with at least the latest released version of superset.
• I have checked the issue tracker for the same issue and I haven't found one similar.

Related to #3326, which is closed but has not been resolved.

Superset version

0.28.1

Expected results

Time is displayed consistently in the same time zone on the calendar heat map as for the data queried. The January day view should start with the 1st of January for example.

Actual results

The January day view starts with the 31st of December 23:00 for setups using CET. The data is queried correctly in UTC, but somehow seems to be displayed in local time zone instead.

Steps to reproduce

• create calendar heatmap
• configure with "day" time grain, "month" domain and "day" subdomain
• observe months starting with the previous months day for time zones east of GTM and all days shifted accordingly

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[ghost]

This issue was moved by kristw to apache-superset/superset-ui-plugins#52.