time an item begins to exist or a statement starts being valid
Conflicts with “inception (P571)”: this property must not be used with the listed properties and values. (Help)Exceptions are possible as rare values may exist. Known exceptions: Roman Kingdom (Q201038), Roman Republic (Q17167), Roman Empire (Q2277)
List of this constraint violations: Database reports/Constraint violations/P580#Conflicts with P571, SPARQL, SPARQL (new)
Single value: this property generally contains a single value. (Help)Exceptions are possible as rare values may exist.
List of this constraint violations: Database reports/Constraint violations/P580#Single value, SPARQL, SPARQL (new)
Conflicts with “date of official opening (P1619)”: this property must not be used with the listed properties and values. (Help)Exceptions are possible as rare values may exist.
List of this constraint violations: Database reports/Constraint violations/P580#Conflicts with P1619, SPARQL, SPARQL (new)
Scope is as main value (Q54828448), as qualifier (Q54828449): the property must be used by specified way only (Help)Exceptions are possible as rare values may exist.
List of this constraint violations: Database reports/Constraint violations/P580#scope, SPARQL, SPARQL (new)
Allowed entity types are Wikibase item (Q29934200), Wikibase property (Q29934218), Wikibase MediaInfo (Q59712033): the property may only be used on a certain entity type (Help)Exceptions are possible as rare values may exist.
List of this constraint violations: Database reports/Constraint violations/P580#allowed entity types, SPARQL (new)
Use of "no value"Edit
In certain items such as Q17, "end date: no value" is used to indicate that the statement is true as of now. In my opinion, it would be better just to leave it blank, as otherwise the qualifier would need to be added to pretty much everything, and additionally can cause statements to be inaccurate as opposed to incomplete if the status changes. Thoughts? --Yair rand (talk) 02:04, 19 June 2013 (UTC)
Two ranges of timeEdit
Say politician A was in political party X from 2005 to 2009. Then he left the party in 2010. Then return to the party in 2012 and left again for the second time in 2013. So this would mean that two qualifier sets of start time (P580) and end time (P582) would be needed for member of political party (P102). How do we signify that start_date1 corresponds to end_date1 and not end_date2? --Wylve (talk) 14:01, 26 June 2013 (UTC)
- The same case is with head of government (P6). I think it could be resolved as separate statements. There is rank available with each statement. For all historical statements the rank is set to normal but for the current one it shall be set to preferred. So in real-life scenario the rank=preferred shall be used with single start time (P580) property and rank=normal if both start time (P580) and end time (P582) are provided. Unfortunately, I could not find method to edit the rank value. It is only visible in Lua scripts as normal. Paweł Ziemian (talk) 11:42, 6 July 2013 (UTC)
- Both Gregorian and Julian calendars are supported. So perhaps you can just pick one and use a backdated date (e.g. 9700 BCE). You are also able to specify precision to century, millenium, etc (under advanced adjustments). Superm401 - Talk 18:45, 1 October 2013 (UTC)
I recently discovered that one can also enter the decade using this property rather than a concrete year or date. This is useful when you only know, as an example, that a certain event took place "about" 1925 – then you enter "1920s". But what if this event did not take place in the middle of the decade but at the beginning/end or turn of the decade? Then it is not clear which decade should be entered.--Leit (talk) 00:05, 5 February 2014 (UTC)
- @Leit: Thank you for bringing this up already six years ago! Have you found an answer elsewhere yet? In my opinion, even specific dates are approximate too, given that you can't specify a higher precision than day (I see there has been a lot of talk about that; I'm not going there now). But your question relates to the issue of matching end/start times of adjacent periods, such as when one person replaces another in a public office, or a geographic entity changes name or political/administrative affiliation.
- If a formal change is declared to take place at a particular date, say January 1st of some year, then the new period is generally assumed to include that entire day, so it effectively begins at 1 January 00:00:00 (midnight, local time). But when does the previous period end? I have seen cases of the end date sometimes specified as December 31 the previous year, sometimes as January 1 of the new year (i.e. identical to the start of the new period). I don't know yet which usage is currently most common on Wikidata, but in general parlance, saying that something ends on January 1st hardly ever means that the old state of things remains true throughout January 1st until 23:59:59 (next to midnight), with the new period commencing only on January 2 00:00:00; it means that the old state of things ceases at the very beginning of January 1st 00:00:00.
- Partly for the reason you mention, but also to make dates of change easier to enter and lists of successive periods easier to read, I would argue that the start time should be viewed as inclusive while the end time is regarded as exclusive. In that way, it won't matter at what precision you know the time of a change; if the new period begins in 1925 (date unknown), the previous period will end "in" 1925 too, and if the new period begins the 1920s, the old one will end in the 1920s too, even if the change actually took place on January 1st, 1920, and you won't have to worry about fencepost errors due to low precision knowledge of when an event took place.
- This argument of course does not apply when you actually have an interim period of transition, such as the vacancy of an office when its previous holder has died or resigned, and the successor has not yet been appointed or been able to effectively take that office into possession.
- As always, anyone's comments are welcome (especially conflicting opinions based on contradictions of the examples I have given). --SM5POR (talk) 12:27, 4 July 2020 (UTC)
How do I specify the exact start and end times of an event? For examples transit of Venus, 1639 (Q3537644) began at 4 December 1639 14:57 and ended at 21:54 UTC. --Mu301 (talk) 22:42, 6 February 2016 (UTC)
I am also having difficulty entering an exact time. For example I put in "May 14th 2017 8:00pm" and it says "will be displayed as +2017-05-14T20:00:00Z" but when I save, I get the error "Could not save due to an error. Malformed input: +2017-05-14T20:00:00Z". This seems to be a bug. Devon Fyson (talk) 05:33, 28 July 2017 (UTC)
Used as qualifier only ?Edit
This property have itself the property instance of (P31) = Wikidata qualifier (Q18615010). Logically, I added the constraint « this property can only be used as a qualifier » (Special:Diff/302962998) and logically too Swpb reverted me (Special:Diff/303185675).
I believed the situation was : « using end time (P582) as qualifiers only and using other and more specific ending property otherwise (date of disappearance (P746), dissolved, abolished or demolished date (P576), date of death (P570), service retirement (P730), etc. depending on the context) » but indeed, the situation seems to be unclear and end time (P582) is used on 11,701 items (some are strange but others seems legit) ; moreover, the description says « The time the claim ended being valid, usually as a qualifier ».
So is it « only » or « usually » ? The information is contradictory and conflicting; it would be better to clarify it.
Same situation for start time (P580).
- I would not even go so far as to say that these properties should "usually" be qualifiers; I think they are perfectly acceptable as item properties in themselves. Surely, for items about events, the meaning of "start time" and "end time" is clear. As you say, the properties are already being widely used that way; I think that is because such use is natural and generally self-explanatory. Swpb (talk) 17:19, 16 February 2016 (UTC)
- Battles and television series seem to be frequent users as a statement property Query
--- Jura 17:52, 16 February 2016 (UTC)
- Battles and television series seem to be frequent users as a statement property Query
- Update (May 2018): See further discussion discussion on Project chat. --Oravrattas (talk) 11:27, 10 June 2018 (UTC)
- The discussion on Project chat was about the difference between P571 (inception) and P580 (start time). In my view, P580 (start time) is better suited for events (not recurring ones, but single events, or instances of recurring events) and event-like items than P571 (inception). So P580 (start time) should not be made qualifier-only. I am surprised that Máté's opinion in the discussion on Project chat is just opposite of mine. I cannot help guessing that Máté probably confused P571 with P580 (sorry if my guess is wrong). I think that P571 (inception) is suited for organizations and other relevant entities, not events.--Neo-Jay (talk) 14:03, 10 June 2018 (UTC)
Merge with P1326 ?Edit
I can't see any objective difference between properties end time (P582) and latest date (P1326). Both should be merged. Or something is missing to distinguish them if there's a difference. Verdy p (talk) 12:18, 28 February 2016 (UTC)
- "end date" = date when an event ends
- "latest date" = any date before and including a given date. Latest date should be a qualifier for date properties in general. It could a qualifier on an "end date" (e.g. unknown"). At some point, date properties should include the difference in precision directly and "latest date" could be deleted.
--- Jura 12:28, 28 February 2016 (UTC)
дата начала процессаEdit
- Не в курсе, я бы моделировал процесс отдельным свойством, где элементы-значения - это стадии процесса.
- Процесс "строительство дома":
- планирование и проектирование
- согласование проектной документации
- передача документов строителям-подрядчикам
- начало строительства, строительство, завершение строительства
- презентация сооружения (праздничное событие)
- введение здания в эксплуатацию
- У стадий можно свойства начала-конца даты указывать как квалификаторы.
- Такой подход позволяет указать нарушения (пропущенное проектирование, "начало процесса" со второй стадии).
- Более опытные участники могут подсказать точную модель. d1g (talk) 18:54, 4 January 2017 (UTC)
Constraint against Event should be removed or replacedEdit
It seems that the Event constraint for an instance type is not appropriate in many cases. The constraint violation report is now VERY large.
For example: cuneiform Q401 is not an event, but a writing style that had an inception or start date and a generally acknowledged end date.
It seems wiser that the constraint should be higher up like 'temporal entity'.
I created that new item for this purpose: https://www.wikidata.org/wiki/Q26907166
Any Thing could have a temporal state. And only 1 thing cannot = Time itself. When a Thing has been determined by common sense or a historical perspective to have had a 'temporal occurance' or happening, then I would think that it could be classed as a 'temporal entity' and not an event. There are no restrictions.
---- Thadguidry (talk) 03:03, 17 September 2016 (UTC)
- Support. Thryduulf (talk) 10:43, 17 September 2016 (UTC)
- Oppose because of the example. A writing system is not an event, it has a period where it's used, but it does not cease to exists after it's end main period of usage and can still be studied or event written later. 14:29, 19 October 2016 (UTC)
- Comment see also Chicago Card (Q5095525) (now defunct) and Ventra (Q7920279). d1g (talk) 15:48, 4 January 2017 (UTC)
Start and end dates for positions heldEdit
These properties are very useful, and widely used in Wikipedia, as qualifiers of positions held by people. However, it is not always clear how a start date and an end date exactly mean in these cases. For example, catholic bishops are "appointed" at a date, and ordained some time later. I would have though the ordination date was the one to be used, but that is not how catholic-hierarchy.org does it (see  and ). For ambassadors, the date might be either when she is nominated or when the hosting country accepts her nomination.
How should we solve it ? Create subproperties so that we can document things in full ? Make a list of events that we shall use for start time (P580) and end time (P582), something else ? --Zolo (talk) 07:31, 13 May 2017 (UTC)
is it possible to add a precision Minute to this Property. I am interested in the history of parliaments and there for example in legislative terms of the German Reichstag from 1871 to 1918. I want to add items for the meetings of the different legislative terms of the German Reichstag in the mentioned time. In the Reichstagsprotokolle you can find the start time and end time of the meetings in a precison of Minute and I think it were great if it is possible to add it. -- Hogü-456 (talk) 18:13, 21 September 2019 (UTC)
- Hogü-456 and Digi-ark, in case you've not yet discovered it, you can use the qualifier refine date (P4241) to provide an exact time for this property. It's not a perfect solution, but it gets the point across. — Huntster (t @ c) 18:40, 23 February 2021 (UTC)