unixepochtime
Formats

Timestamp Format Converters

Convert between Unix timestamps and the platform-specific time formats you meet in the wild — Windows FILETIME, .NET ticks, Chrome/WebKit, Apple Core Data, Excel serial dates, NTP, GPS time, and Julian Day.

FILETIME Converter

Paste a Windows FILETIME value and convert it to a Unix timestamp (seconds and milliseconds), ISO 8601, and a human-readable date in any timezone. FILETIME counts 100-nanosecond intervals since January 1, 1601 UTC.

.NET Ticks Converter

Convert a .NET DateTime.Ticks value to a Unix timestamp in seconds and milliseconds, ISO 8601, and a readable date. .NET ticks count 100-nanosecond intervals since January 1, 0001.

WebKit/Chrome Time

Convert a Chrome/WebKit timestamp — microseconds since January 1, 1601 UTC — to a Unix timestamp and readable date. Common in Chrome history, cookies, cache, and other SQLite-backed browser artifacts.

Mac Absolute Time

Convert Apple’s Mac Absolute Time (CFAbsoluteTime) — seconds since January 1, 2001 UTC — to a Unix timestamp, ISO 8601, and a readable date in any timezone.

Core Data Timestamp

Convert a Core Data timestamp — seconds since January 1, 2001 UTC — to a Unix timestamp, ISO 8601, and a readable date. Core Data stores dates using Apple’s CFAbsoluteTime reference date.

Excel Date Converter

Convert an Excel serial date or OLE Automation Date (OADate) to a Unix timestamp, ISO 8601, and a readable date. Explains the 1900 date system and the famous Excel 1900 leap-year bug.

NTP Timestamp

Convert an NTP timestamp — seconds since January 1, 1900 UTC — to a Unix timestamp, ISO 8601, and a readable date. Covers the NTP epoch, eras, and why a fixed offset is not always enough.

GPS Time Converter

Convert GPS time — seconds since January 6, 1980 with no leap seconds — to a Unix timestamp and readable UTC date. Explains the GPS epoch and how GPS time diverges from UTC by leap seconds.

Julian Day Converter

Convert a Julian Day (JD) or Modified Julian Day (MJD) to a Unix timestamp, ISO 8601, and a readable date. Julian dates are the standard continuous day count used in astronomy and many scientific datasets.

Convert any timestamp format to Unix time

Different platforms count time from different epochs and in different units. These converters translate each of those platform-specific formats to and from a standard Unix timestamp, ISO 8601, and a readable date in any timezone. Pick the format you are working with:

Not the format you need?

For plain Unix timestamps in seconds or milliseconds, use the main converter. To understand how these formats differ, read the formats guide.

Choosing between similar formats

A few of these formats overlap closely — knowing which is which prevents the most common conversion bugs:

  • FILETIME vs WebKit: same 1601 epoch, but FILETIME is 100-ns ticks while WebKit is microseconds — they differ by 10×
  • Mac Absolute Time vs Core Data: identical CFAbsoluteTime reference (seconds since 2001) — use either converter
  • .NET ticks vs FILETIME: same 100-ns resolution, but .NET counts from year 1, FILETIME from 1601 — a fixed 504911232000000000-tick offset
  • Julian Day vs Modified Julian Day: MJD = JD − 2400000.5; MJD starts at midnight, JD at noon
  • Excel 1900 vs 1904 systems: different origins; the 1900 system also has the famous fake-leap-year bug for day 60