Convert times across world timezones and compute exact business days.
Execution runs 100% locally inside the browser sandbox using HTML5 Canvas, Web Cryptography Subtle API, and Web Workers. Zero egress.
Zero network latency. Operates completely offline with zero dependencies on third-party backend servers or cloud services.
Built according to official RFC specifications, cryptographic test vectors, and enterprise-grade data transformation standards.
Choose your base time and origin timezone.
Add major global cities and timezones (UTC, New York, London, Tokyo, Sydney).
Inspect simultaneous time conversions and daylight saving time (DST) offsets.
Yes, it uses the IANA Time Zone Database embedded in the browser's Intl API for accurate DST shifts.
Yes, the tool includes a date difference calculator for days, business days, and hours.
Zero-egress companion tools in the Date & Time suite
Convert Microsoft Excel 1900 date system serial integers into standard ISO 8601 timestamps.
Calculate continuous Julian Day Numbers (JDN) and Modified Julian Date (MJD) from Gregorian dates.
Convert high-precision 19-digit nanosecond timestamps into formatted UTC strings.
Check exact clock shift dates and hour offsets for US, EU, and global timezones.
