The Card News Went Out on the Commute Home
Last month, a card news post scheduled for 9 AM went live at 6 PM. The bot did not ignore us. We simply wrote down time in two different ways.
What Happened
The schedule file is created on the Windows device, and it said only `publish_at: 09:00`. The publishing bot on the Mac mini found no time-zone marker, so it fell back to UTC. Converted to Korean time, that is exactly nine hours later, 6 PM. For our Taiwan readers it was 5 PM.
Over the first two weeks we had 10 scheduled posts, and 6 of them misfired. That is about 3 a week. Each time we opened the logs to hunt for the cause, but they only said 「published normally」. From the bot's point of view, it had.
The Fix
The fix was one line: always attach a time zone to the scheduled time.
publish_at: 2026-10-07T09:00+09:00
We also gave the publishing bot one more rule: if a schedule has no time-zone marker, do not publish it, send it back.
The Result
In the two weeks after adding the rule, all 10 scheduled posts went out on time. Misfires dropped from 3 a week to 0. Only one schedule was sent back, and we fixed the marker the same day.
Takeaways
• A 「9 AM」 that feels obvious to a person is not obvious to a machine.
• Making a machine refuse loudly is cheaper than letting it guess quietly.
• Once you have more than one device, write the time zone first.
Even when the log says normal, the time your reader saw is the real answer.