Markus Zolliker
8663501150
- created secop_v2017-09-14.rst, based on the GoogleDocs SECoP Preliminary V2016-11-30 (rc 2) - this Document is supposed to contain the full SECoP standard - created SECoP issues - moved everything else to "outdated" (kept for reference) Change-Id: I87d69d1846fc4ed55f1c78b22fd4650d8550152b Reviewed-on: https://forge.frm2.tum.de/review/16573 Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de> Tested-by: JenkinsCodeReview <bjoern_pedersen@frm2.tum.de>
48 lines
1.5 KiB
ReStructuredText
48 lines
1.5 KiB
ReStructuredText
SECoP Issue 3: SECoP Timestamp Format (closed)
|
|
==============================================
|
|
|
|
Proposals for the timestamp format are:
|
|
|
|
ISO time format
|
|
---------------
|
|
|
|
A date+time string in ISO format like "2017-06-21T13:30:01.123456+02:00"
|
|
|
|
The fractional seconds are optional, but the timezone has to be given. Z is allowed instead of +00:00.
|
|
|
|
Advantages:
|
|
|
|
* human readable
|
|
|
|
Disadvantages:
|
|
|
|
* needs more conversion efforts, as the time is internally already stored as numbers on mosts systems (supporting math operations).
|
|
* although the ISO standard is clearly defined, there is a risk that time zones and daylight saving time is not handled properly
|
|
|
|
Fractional Unix Time
|
|
--------------------
|
|
|
|
Seconds since 1970-01-01T00:00:00+00:00, represented as a number. When converted to a IEEE double, a resolution of 1 usec can be kept for dates up to 2112.
|
|
|
|
Advantages:
|
|
|
|
* if a double is used as an internal representation, no conversion is needed. using a double as an internal time representation has the advantage, that math operations can be done for free.
|
|
* relative times for systems with no synchronized clock can be represented easily
|
|
|
|
Disadvantages:
|
|
|
|
* not human readable (or at least not easily: time differences in seconds are still visible)
|
|
|
|
|
|
Discussion
|
|
----------
|
|
|
|
1) Human readibility was judged less important than easy implementaion by the majority.
|
|
|
|
2) Implementing relative times is also easier.
|
|
|
|
Decision
|
|
--------
|
|
|
|
At the meeting in Berlin (2017-05-30) the attendes decided for "Fractional Unix Time".
|