Lines Matching +full:conversion +full:- +full:rate
11 nominally constant rate from zero at the instant the system started. The POSIX
19 discontinuities due to `leap seconds <https://what-if.xkcd.com/26/>`__ and
48 <https://tools.ietf.org/html/rfc8536#section-2>`__.
61 Sub-second timestamps like ``struct timespec`` can also use this to produce
62 the calendar time representation and deal with sub-second offsets separately.
77 * The rate of discrete instant representation change. For example Zephyr
84 conditioned by a 1-pulse-per-second GPS signal will be much more accurate
85 than a Zephyr system clock driven by a RC oscillator with a +/- 250 ppm
88 Synchronization or alignment between time scales is done with a multi-step
91 * An instant in a time scale is represented by an (unsigned) 64-bit integer,
92 assumed to advance at a fixed nominal rate.
100 relative errors in the actual rate of each time scale.
115 <https://www.loc.gov/standards/datetime/iso-tc154-wg5_n0038_iso_wd_8601-1_2016-02-16.pdf>`__
116 (ISO/WD 8601-1) and elsewhere:
154 `POSIX Time <https://tools.ietf.org/html/rfc8536#section-2>`__ is a time scale
155 that counts seconds since the "POSIX epoch" at 1970-01-01T00:00:00Z (i.e. the
157 <https://tools.ietf.org/html/rfc8536#section-2>`__ is an extension of POSIX
164 <https://tools.ietf.org/html/rfc8536#section-2>`__ which is UNIX time plus all
165 leap-second corrections added after the POSIX epoch (when TAI-UTC was 8 s).
168 ---------------------------------
177 UTC Date UNIX time TAI Date TAI-UTC UNIX Leap Time
179 1970-01-01T00:00:00Z 0 1970-01-01T00:00:08 +8 0
180 1999-12-31T23:59:28Z 946684768 2000-01-01T00:00:00 +32 946684792
181 1999-12-31T23:59:59Z 946684799 2000-01-01T00:00:31 +32 946684823
182 2000-01-01T00:00:00Z 946684800 2000-01-01T00:00:32 +32 946684824
183 2016-12-31T23:59:59Z 1483228799 2017-01-01T00:00:35 +36 1483228827
184 2016-12-31T23:59:60Z undefined 2017-01-01T00:00:36 +36 1483228828
185 2017-01-01T00:00:00Z 1483228800 2017-01-01T00:00:37 +37 1483228829
189 -----------------------
196 There are two stages required to support conversion between Zephyr time and
212 -------------------------------------------
224 - GPS time: epoch of 1980-01-06T00:00:00Z, continuous following TAI with an
225 offset of TAI-GPS=19 s.
226 - Bluetooth Mesh time: epoch of 2000-01-01T00:00:00Z, continuous following TAI
227 with an offset of -32.
228 - UNIX Leap Time: epoch of 1970-01-01T00:00:00Z, continuous following TAI with
229 an offset of -8.
231 Because C and Zephyr library functions support conversion between integral and
236 involve reading from a local high-precision RTC peripheral, exchanging packets