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So, I noticed DateTime.MinValue defaults to 01-01-0001 (dd-MM-yyyy), so for example let's say we have a museum database/class object whatever, how do you store an object that is from 10,000 BC or how about dinosaur bones that are from millions of years prior to today?

Can it be a signed value? like, the year "-10000" represents BC? or we would need to rely on strings and be unable to natively work with dates prior to year 1?

I checked this question out that asks for year zero, but it doesn't have any helpful insights, other than apparently not everyone knows there is no such thing as year zero. how make a datetime object in year 0 with python

FObersteiner
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SGP
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    Does this answer your question? [What is the best way to handle bc dates in .net / sql server?](https://stackoverflow.com/questions/5058709/what-is-the-best-way-to-handle-bc-dates-in-net-sql-server) – openshac Oct 14 '21 at 19:25

2 Answers2

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No, DateTime doesn't handle anything before 1CE.

My Noda Time project does support BCE dates, but still limited to about 9998 BCE as the earliest it can handle.

Once you're talking about prehistoric times, you probably have a different set of use cases from normal date/time types anyway - so just extending the range of the existing types may well not help you much. (As an example, quite often ancient history deals with relative dates: "I know battle X took place 3 years into the reign of king Y, but I don't know exactly when either of them happened.") I'd suggest you think about what your actual use cases are, and what you need to do with the date/time information. Then you can look into whether existing libraries meet your needs, or whether you need to write your own abstractions.

Jon Skeet
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After digging around, I've found that other than creating one's own types, there is no easy native solutions to this specific use case for dates, so I want to propose my solution in case its of use to anyone. Just add a column that will have a sign, a - and a + (or a 0 and 1 I guess with a boolean type). Dates with + are AC and dates with - are BC. On your code or otherwise you'll have to handle the sign. Its simple and requires no extra libraries or technologies.

Since dates have no zeros the sign should not create interference, and just minding negative dates move in reverse order in your logic will solve any issues with that. However this solution only works for dates up to year 9999, so in order to be able to handle even farther away dates, a more complex sistem would have to be programmed. like handling each part of a date in a separate column so it can cover as many years as int or double can do numbers.

However, I do think positive dates from the year 3000 up to the year 9999 will hardly ever be used, much less towards millions of years into the future. But maybe it will be of use for fan proyect databases for sci-fi universes like 40K or SW or ST.

SGP
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