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For old data that is @db.Timestamp but should be a plain date, store it as yyyy-mm-dd 00ddT00:00:0000Z (midnight UTC). Use the transformer mentioned above.
Testing
A good idea to include manual tests for dates and times that involve times within 4 hours of midnight in either direction to make sure the feature doesn’t mess up the time displayed. Remember that the default timezone is ET, so it should at least work as expected in this time zone.
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