Talk:System time

message: I removed the following edit by 70.228.163.254:
:... (however, the Commodore 64 and Commodore 128 both had time-of-day clocks and precision 32 bit interval timers).
The point of that paragraph is to point out that early PC hardware did not track system time. Obviously, later hardware and operating systems did, but it is pointless to list any of them in this article. — Loadmaster (talk) 20:31, 25 November 2007 (UTC)
thread_title:  Early PCs lacking clocks 

message: Does anyone have a good reference as to what system(s) was the first to track system time? It would make a good start for a "History" section, which could include the current paragraph that mention early PC systems. — Loadmaster (talk) 01:40, 26 March 2008 (UTC)
thread_title:  History 

message: The article's first section (Retrieving system time) begins with
:According to the Wikipedia system clock, the current time is .
This does not work so well for users browsing anonymously, as explained in WP:BYPASS#Server cache, though it works great for users who are logged in.  Basically, all anonymous users see the same page—preferences do not affect the layout—so Wikimedia's squid (software) serves up the cached copy of the page.  They'll see the time when it was cached.  Updating the page (making an edit) also causes the cache to update, so that's why it sometimes seems to work.  —EncMstr (talk) 20:04, 2 May 2008 (UTC)
replies: text: It's also interesting to Google for this page as it appears in other online references, which gives the time that those copies were last retrieved from Wikipedia. — Loadmaster (talk) 20:20, 17 June 2008 (UTC)
thread_title:  CURRENTDATE 

message: The table summing up the tick resolutions says that C#'s resolution is 10 msec.
However, the online documentation tells that the resolution is 100 nanoseconds. I'm going to correct the values for C# and Visual Basic. And Powershell, while we're at it.  —Preceding unsigned comment added by Ruijoel (talk • contribs) 08:23, 28 May 2008 (UTC)
thread_title:  correcting C# tick resolution 

message: There are other date/time pages at
http://www.merlyn.demon.co.uk which might be considered to be at least as germane as CritDate. 82.163.24.100 (talk) 13:00, 17 December 2010 (UTC)
thread_title:  External links 

message: 2-12 μs is NOT 244.14 ps; I believe the latter. 82.163.24.100 (talk) 13:19, 17 December 2010 (UTC)
replies: text: Yes, it is. The key to understanding this is that the operation of raising 2 to the negative 12 power is performed first, and then the μs unit is associated with the resulting number. So it is 2.44  μs which is equal to 244 ps. Jc3s5h (talk) 15:31, 17 December 2010 (UTC)
thread_title:  Operating Systems 

message: Epoch or range column :
Needs a clear indication of whether UTC, GMT, local, or other.
"Midnight of the current day" is in principle ambiguous.  Use "Start", "Beginning" or "00:00".
In several cases, the end is not at 00:00 - that should be indicated.
Next table : JavaScript - new Date() seems better.  Range is +- 10^8 days.
82.163.24.100 (talk) 13:28, 17 December 2010 (UTC)
replies: text: I addressed this for IBM z/Architecture, which uses UT. For current systems it uses UTC, but that did not exist for the entire time range, and might not exist for the remainder of the time range. For information about possible changes to, and renaming of, UTC, see Leap second. Jc3s5h (talk) 16:12, 17 December 2010 (UTC)
thread_title:  Operating systems 

message: This article does not appear to follow any particular citation format. The first citation was added in this edit, and appears to be a plain-language description of the source rather than following any recognized style. So if I were to standardize the format, what format should I use? Jc3s5h (talk) 12:30, 17 October 2011 (UTC)
replies: text: Per WP:CITE#Citation style, there is no agreed upon standard.  Use whichever you are most comfortable with.  —EncMstr (talk) 16:23, 17 October 2011 (UTC)
replies: text: I have made the citations consistent, using The Chicago Manual of Style. Jc3s5h (talk) 16:47, 27 October 2011 (UTC)
thread_title: Citation format

message: There is a distinction between the resolution or granularity at which a system keeps or reckons time, and the resolution with which time is reported. For example, in Microsoft Windows, GetSystemTimeAsFileTime indeed returns a 64-bit integer that reflects the number of 100 nsec intervals since 01 Jan 1601. However the system does not keep time with anything like that fine a granularity; timekeeping is driven by an interval timer interrupt with a typical default period of 15.625 msec (64 Hz), settable to as little as 1 msec or 0.5 msec 
for software that needs better resolution. 
This distinction should be made in the table that compares operating systems. I suggest three adjacent columns, labeled perhaps "Resolution (reported)", "Resolution (implemented, default)", and "Resolution (implemented, best)". I have only information on Windows and VMS so I can't make much of a start here. I suggest that we add information to this section and then make the change to the article when enough cases are described so that we don't have a mostly-empty column. Jeh (talk) 18:33, 8 July 2012 (UTC)
replies: text: You are talking about the difference between resolution and precision. As the tables stand now, it is more relevant to display the units returned by the OS or programming language call, i.e., the resolution, and footnotes should suffice for explaining the actual accuracy/precision of the value returned by the call. For future editions of the tables, though, instead of adding another column we should perhaps expand the "Resolution" column to include both, i.e., "Resolution and Precision", which displays the resolution (time units returned by the call) and also parenthetically displays the range of actual/expected accuracy. Perhaps using a notation such as "" (specifying a resolution of 1ms and a precision of 10ms) might also suffice. — Loadmaster (talk) 18:04, 11 July 2014 (UTC)
thread_title:  Resolution column in tables