TAI64 Timestamps

The current TAI64 timestamp is: 400000005497c147

UTC Date (yyyy-mm-dd 24hh:min:sec): - -    : :


Result:

What is a TAI64 timestamp?

	TAI64 is a 64 bit timestamp format created by D. J. Bernstein.  Here is 
	what Daniel has to say about the format:

	1. Introduction

	Today's UNIX systems, and many Internet protocols, store times as signed
	32-bit integers representing the number of seconds since the beginning
	of 1970. This format will expire in 2038.

	Other systems, and other protocols, store times as unsigned 32-bit
	integers representing the number of seconds since 1900. This format will
	expire in 2036.

	This document defines a 64-bit format, TAI64, suitable for use in new
	systems and protocols. TAI64 represents a few hundred billion years of
	real time with 1-second precision.


	2. The TAI64 timescale

	TAI stands for Temps Atomique International, the current international
	real time standard. One TAI second is defined as the duration of
	9192631770 periods of the radiation corresponding to the transition
	between the two hyperfine levels of the ground state of the cesium atom.
	(TAI also specifies a frame of reference; further discussion of
	relativity is outside the scope of this document.)

	TAI64 defines integer labels, between 0 and 2^64, for particular seconds
	of real time. If 2^62 <= n < 2^63 then label n refers to the TAI second
	beginning exactly n - 2^62 seconds after the beginning of 1970 TAI. If
	0 <= n < 2^62 then label n refers to the TAI second beginning exactly
	2^62 - n seconds before the beginning of 1970 TAI.

	For example, label 4611686018427387904 refers to the second beginning at
	the start of 1 January 1970 TAI. Label 4611686018427387903 refers to the
	previous second; label 4611686018427387905 refers to the next second.

	Labels 2^63 and larger are currently reserved for future extensions.
	Under many cosmological theories, the labels under 2^63 are adequate to
	cover the entire expected lifespan of the universe; in this case no
	extensions will be necessary.


	3. The TAI64 format

	A TAI64 label is stored or communicated in eight 8-bit bytes in
	big-endian format. This means that bytes b0 b1 b2 b3 b4 b5 b6 b7
	represent the label b0 * 2^56 + b1 * 2^48 + b2 * 2^40 + ... + b7.

	For example, bytes 64 0 0 0 0 0 0 0 represent the second that began
	1970 TAI. Bytes 63 255 255 255 255 255 255 255 represent the previous
	second; bytes 64 0 0 0 0 0 0 1 represent the next second.

	Bytes 64 0 0 0 52 53 54 55 represent 3 October 1997 18:15:19 TAI, also
	known as 3 October 1997 18:14:48 UTC.


	4. Handling fractional seconds

	One-second precision is inadequate for many applications. This section
	defines 96-bit and 128-bit formats, TAI64N and TAI64NA, with nanosecond
	and attosecond precision respectively.

	A TAI64N label refers to a TAI nanosecond. It has two parts: (1) a
	second count, meaning a TAI64 label; (2) a nanosecond count, meaning an
	integer between 0 and 999999999 inclusive. It is stored in twelve 8-bit
	bytes, with the TAI64 label followed by the nanosecond count in
	big-endian format.

	A TAI64NA label refers to a TAI attosecond. It has three parts: (1) a
	second count; (2) a nanosecond count; (3) an attosecond count, meaning
	an integer between 0 and 999999999 inclusive. It is stored in sixteen
	8-bit bytes, with the TAI64 label followed by the nanosecond count in
	big-endian format and then the attosecond count in big-endian format.
	

Comments? Email info at this domain.