Timestamps

Converts computer timestamps both ways and shows a moment in every format: Unix seconds and milliseconds, GPS week and seconds (with IERS leap seconds), Windows FILETIME, Chrome/WebKit, .NET ticks, Excel serial, NTP, Apple, XRP Ledger, MJD and Julian Date, counted exactly in 100-nanosecond ticks. Unix time counts seconds since 1970-01-01 00:00 UTC without leap seconds; FILETIME counts 100-nanosecond intervals since 1601.

• The Open Group Base Specifications (IEEE Std 1003.1), “Seconds Since the Epoch”
• Microsoft, “FILETIME structure”, Win32 API documentation
• IERS, leap-seconds.list (Bulletin C)