The 100 city time zone page provides quick reference for inter-regional scheduling, with DST calculated automatically.

100 Time Zone Pages for Cross-Area Scheduling as Quick Reference, DST Automatic Calculation

The author is a developer in the data pipeline / cross-time zone scheduling direction. This article is not an advertisement, but a record of pitfalls + tools made along the way.

When doing data pipelines / cross-time zone scheduling, timestamp conversion is often the most underestimated minefield. 16 timestamp tools (Unix conversion / time zone / ISO8601 / Cron / Duration ...) have covered daily needs; but each language / framework has its own pitfalls, so I added 30 language / framework timestamp pages (python / javascript / java / sql / ...), each containing 6 real pitfalls.

Some of the pitfalls I've encountered (a few examples):

Seconds vs Milliseconds: frontend Date.now() is in milliseconds, while backend often stores in seconds, with a 1000-fold difference.

Time zone is not a string: store in UTC, display in local time, and don't treat local time as UTC when storing.

2038 problem: 32-bit system time_t overflows on 2038-01-19, so old systems need to be checked in advance.

Daylight Saving Time: there are two repeated / missing local times a year, which is especially problematic for cross-area scheduling.

Things I've made along the way:

Timestamp Quick Reference Page: https://gotimestamp.com/timezone/new-york

Related Language Pages: https://gotimestamp.com/timezone/london

Open-source MCP: https://github.com/caresotin/tsforge-mcp - directly connects timestamp conversion / verification to LLM workflow, no manual calculation needed.

In conclusion, timestamps are not that simple, but with the right tools, it's a breeze. All of the above are free, open-source, and directly usable, and I hope they help those who have encountered similar pitfalls.