RDS Custom for SQL Server now supports Local Time Zones… but why would you want to?


After over two decades in tech. I have learned there are three things you never, ever, ever want to mess with short of research or a group of PhD’s:

  • date
  • time
  • cryptography

But here we are. AWS adding custom time zones. I think Corey Quinn said it best:

RDS Custom for SQL Server now supports Local Time Zones – No. Absolutely not. NO. There is one true timezone for servers and databases, and it’s UTC. It’s a one-way door that you don’t realize you’re passing through and then you spend decades unpacking the mess. Google learned this with “Google Standard Time.” Yes, yes, “most things never need to transcend multiple timezones” and that’s correct right up until suddenly they do. Display whatever timezone you like at the presentation layer, but the data layer should store time in UTC, and optionally a timezone offset.

– [Last Week in AWS] Issue #330: EC2’s Weird Flex

Please, heed this warning. Keep your SQL in UTC, alter timezone at the presentation layer.

You have been warned.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.