Since mongo by default stores the dates in UTC timezone, whenever we have to create a chart based on the time, we need to always go to the `customize` section and change the timezone. It's a repetitive process and sometimes people forget, and end up exporting wrong data. (A major use-case for charts for us is also self-serve data export by non tech users) We can change the timezone using an aggregation pipeline, but that changes the data type itself from date to number (by splitting into day, month, hour etc); and then it's manual work in the chart UI to merge them back. So a very useful feature might be to set a default timezone for all timestamps in the data (for all charts or maybe at a dashboard level) so that we don't have to set it manually using the customize tab every time.