Often, it's best practice to store time in both epoch (UTC) format and the actual time zone when the transaction/event occurred. Epoch time can be the universal

Often, it's best practice to store time in both epoch (UTC) format and the actual time zone when the transaction/event occurred. Epoch time can be the universal truth, used for business rules and it can be displayed in whatever time zone the user prefers. The event's actual time zone can be used for analytics and other research purposes, but for critical business decisions or rules.