Timezones in scheduled publishing

It sounds simple: the user says "publish at 10:00" and the post goes out at 10:00. But as soon as you dig in, questions appear.

10:00 in which timezone? How does it shift with daylight saving time? What if the user changed their timezone after scheduling the post?

We spent time getting time handling right inside our service. Conclusion: store everything in UTC and convert only at the UI layer — it's not just a best practice, it's the only way not to get confused.

Simple things that turn out to be complex — a good reminder not to underestimate details.