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.

Timestamp formats do not all start at the Unix epoch. Windows, Apple platforms, Excel, NTP, GPS, and WebKit use different reference dates or units. These tools convert those values to Unix time while showing the original contract.

What to identify before converting

The source epoch: when does zero occur?
The unit: seconds, days, microseconds, or 100-nanosecond intervals?
Whether the value includes leap seconds or a calendar-specific adjustment.
Whether the number is large enough to require BigInt rather than a JavaScript Number.

A 16-digit value is not automatically “a Unix timestamp with more precision.” It may be a WebKit microsecond value since 1601, a database-specific counter, or something else entirely. The name of the field matters as much as the digits.