Timestamp Format Reference — Every Format Explained

TIMESTAMP FORMATS

every timestamp format supported by unixtime.wtf, with epoch references, common use cases, and conversion notes. click any format to convert it now.

STANDARD FORMATS

Unix timestamp (seconds)

→ convert

seconds elapsed since 1 January 1970 00:00:00 UTC

EPOCH1 Jan 1970 (Unix epoch)

UNITseconds

RANGE10-digit integer (e.g. 1714521600)

USED INLinux/Unix systems, most programming languages, databases, APIs

Unix timestamp (milliseconds)

→ convert

milliseconds elapsed since 1 January 1970 00:00:00 UTC

EPOCH1 Jan 1970

UNITmilliseconds

RANGE13-digit integer (e.g. 1714521600000)

USED INJavaScript Date.now(), Java, most web APIs

ISO 8601

→ convert

international standard for date and time representation

EPOCHn/a (calendar-based)

UNITn/a

RANGEe.g. 2024-05-01T00:00:00.000Z

USED INREST APIs, JSON payloads, HTML datetime attributes, logging

RFC 2822

→ convert

date format used in email headers and HTTP

EPOCHn/a

UNITn/a

RANGEe.g. Wed, 01 May 2024 00:00:00 +0000

USED INemail (From/Date headers), HTTP (Last-Modified, Date headers)

Human readable

→ convert

unambiguous long-form date and time for display

EPOCHn/a

UNITn/a

RANGEe.g. Wednesday, 1 May 2024, 00:00:00 UTC

USED INuser interfaces, logs intended for human reading

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PLATFORM-SPECIFIC FORMATS

Windows FILETIME

→ convert

100-nanosecond intervals since 1 January 1601

EPOCH1 Jan 1601

UNIT100-nanosecond intervals

RANGE18-digit integer (e.g. 133590720000000000)

USED INWindows file system metadata, Active Directory, NTFS, Win32 API

Apple Cocoa time

→ convert

seconds since 1 January 2001, used across Apple platforms

EPOCH1 Jan 2001

UNITseconds

RANGE9-digit integer (e.g. 735696000)

USED INmacOS, iOS, Core Data, Swift Date, Objective-C NSDate

Excel serial date

→ convert

days since 30 December 1899, with an intentional leap year bug inherited from Lotus 1-2-3

EPOCH30 Dec 1899 (with Lotus leap year bug)

UNITdays (decimal for time)

RANGE5-digit integer (e.g. 45413)

USED INMicrosoft Excel, Google Sheets, LibreOffice Calc

NTP timestamp

→ convert

seconds since 1 January 1900, used in network time synchronisation

EPOCH1 Jan 1900

UNITseconds

RANGE10-digit integer (e.g. 3924451200)

USED INNTP protocol, network infrastructure, time servers

GPS timestamp

→ convert

week number plus time of week in seconds, epoch 6 January 1980

EPOCH6 Jan 1980

UNITweeks + seconds

RANGEe.g. Week 2312, ToW 86400

USED INGPS receivers, satellite navigation, geospatial data

.NET DateTime ticks

→ convert

100-nanosecond intervals since 1 January 0001

EPOCH1 Jan 0001

UNIT100-nanosecond intervals

RANGE18-digit integer (e.g. 638495424000000000)

USED INC# DateTime, .NET Framework, Azure, SQL Server datetime2

WebKit timestamp

→ convert

microseconds since 1 January 1601, used in browser history databases

EPOCH1 Jan 1601

UNITmicroseconds

RANGE17-digit integer

USED INChrome browser history (History SQLite database), WebKit internals

TAI (International Atomic Time)

→ convert

continuous atomic timescale, currently 37 seconds ahead of UTC

EPOCH1 Jan 1970 (aligned)

UNITseconds

RANGEUnix value + 37

USED INprecision timekeeping, scientific instruments, GPS ground systems

Julian Day Number

→ convert

continuous count of days since 1 January 4713 BC (Julian calendar), noon UTC

EPOCH1 Jan 4713 BC noon

UNITdays (decimal for time)

RANGE7-digit number (e.g. 2460431.5)

USED INastronomy, astrophysics, calendar calculations

Modified Julian Date

→ convert

Julian Day Number minus 2,400,000.5, epoch 17 November 1858

EPOCH17 Nov 1858

UNITdays

RANGE5-digit number (e.g. 60431.0)

USED INsatellite tracking, VLBI astronomy, space agencies

Lilian Date

→ convert

days since the Gregorian calendar reform, 15 October 1582

EPOCH15 Oct 1582

UNITdays

RANGE6-digit integer (e.g. 161041)

USED INIBM mainframe systems (z/OS), legacy enterprise software

Unix Day

→ convert

whole days elapsed since the Unix epoch — floor(Unix seconds / 86400)

EPOCH1 Jan 1970

UNITdays

RANGE5-digit integer (e.g. 19843)

USED INdatabase date partitioning, Apache Spark, data warehousing, BigQuery

SPECIALIST TOOLS

JWT decoder

→ open tool

paste a JWT token and decode all timestamp fields (iat, exp, nbf) with validity status

Cron parser

→ open tool

paste a cron expression and see the next 10 scheduled run times in your timezone

Relative time

→ open tool

convert natural language expressions like "3 days ago" or "next Friday" to and from Unix

Batch converter

→ open tool

paste a log snippet with mixed formats and normalise to a single output format

GPS timestamp

→ open tool

convert between GPS week/ToW and Unix timestamp

Julian Day Number

→ open tool

convert between Julian Day Number and Unix timestamp