People ask "why UTC"? Good question. Here's why: You can always translate UTC to a local time in a given timezone. With IANA zoneinfo, you can do that corre

People ask "why UTC"? Good question. Here's why: You can always translate UTC to a local time in a given timezone. With IANA zoneinfo, you can do that correctly even for historical data in places where timezone rules changed in the past. You can always calculate elapsed times correctly by taking differences between UTC timestamps. With local times you can't. Because daylight time transitions. If you started with a local service, UTC lets you expand globally without explaining to your new customers why your timestamps are not in their timezones. Daylight time transition days. Because daylight time. Oddball daylight transition rules. Because Indiana USA, from the legislature that almost wrote a law declaring the value of π to be 22/7. Because almost everybody will understand your decision, even after you're gone.