What Chrono Tools Is
Chrono Tools is a collection of 10 free date and time calculators and converters: Unix timestamps (both directions), X post timestamp decoding, timezone conversion across the full IANA database, Julian day numbers, the Chinese lunar calendar, the Hebrew calendar, date differences, ordinal day numbers, leap year checking, and live countdowns. Every tool runs entirely in your browser — the dates and timestamps you enter are never sent to a server.
Why We Built It
Time math looks simple and bites hard: seconds versus milliseconds, daylight saving shifts, leap centuries, lunar leap months, Hebrew months that number to thirteen. Most sites give you one cramped field and an answer with no explanation. We wanted tools that show their assumptions, handle the edge cases, and explain the answer in plain language.
How the Tools Work
Conversions use standard, published algorithms — the Fliegel–Van Flandern Julian day formula, the Gregorian leap rule with its century exceptions, the Twitter Snowflake timestamp layout, and the browser's built-in IANA time zone and Hebrew calendar databases. The core date logic is covered by an automated test suite verified against known reference values before publication.
Our Standards
Each page states exactly what its tool does and where its limits are: animated WebP frames can't be re-encoded client-side, lunar conversion covers 1900–2100, and formal religious observance dates should be confirmed with an authority calendar. If a tool can't do something, the page says so.
The Short Version
Free tools, no accounts, no uploads, tested math, stated limits, and a working contact path. That's the whole promise.