Reading
Short, specific articles about how computers actually handle time — the parts that quietly break software, and the tools that fix them.
Fundamentals
From sundials to the Unix epoch — why we count time the way we do.
Three systems for the same thing, and why they quietly disagree.
The one-second bug that has taken down real production systems.
Why the map of timezones keeps changing under your code's feet.
The quiet protocol keeping millions of clocks in agreement.
The date bug baked into every 4-digit year, centuries from now.
How Unix time represents every date before 1970.
The two atomic timescales behind every clock, 37 seconds apart.
What actually replaces the broken old Date object.
The one calendar unit with no astronomical basis at all.
The zigzagging, never-officially-adopted line where the calendar flips.
Sunday-first vs. Monday-first, and where each convention comes from.
Debunking the Benjamin Franklin myth, and what actually happened.
Julian vs. Gregorian, and ISO week dates that don't line up with the year.
For developers
The seconds-vs-milliseconds mistake, and why it's so easy to make.
A plain-English explainer, from the epoch to the Year 2038 problem.
Three formats, three different jobs — and where they get mixed up.
Why every API seems to do it differently, and how to design your own.
The date format you should probably already be using.
What's really happening when a schedule string triggers a job.
Excel's 1900 bug, Mac's 1904 epoch, and other quiet inconsistencies.
The trick behind messages that show the right time for everyone.
What p1234567890123456 means, and how it maps to the ts field in Slack's API.
How the snowflake ID format works, and how to decode one in JS or Python.
Sorting, range queries, and format drift all fail the same quiet way.
DATE vs. TIMESTAMP vs. TIMESTAMPTZ, and why the choice matters.
Why Date silently assumes the server's local timezone, and how to stop it.
Naive vs. aware datetimes, and the bug that hides between them.
Practical
The specific ways DST breaks schedules, logs, and duration math.
Two overflow bugs, a generation apart — and what changed in between.
A practical checklist for storing and displaying time correctly.
One string, two countries, two different dates — and no error to warn you.