(Click to enlarge)

The defaults are to allow dates +/- 10 years around the current year.

You can add field options like...

min_year=1900,max_year=2100

I do think there's a UX issue here, I'm thinking about it.

Automated response: Vagueness in documentation for date fields

The default date range is +/- 10 years around the current year. This isn't made explicit.

For v11 the default min is now 0ad and the default max is now 3000ad. If you want years around the current year you can do like min_year=Y-10,max_year=Y+10.

Just a note to say this issue also affects gallery dates and not sure how to work around that or if a fix exists in v11.

I tested change the add date for a gallery to 2000, no issue.
I tested adding a custom field to galleries with the field options specified in my first comment, no issue. Did you use the field options?

The date I was trying to add is in the year 1989, I was using/editing the gallery added date for ordering. If I use a custom catalogue field then not sure how to sort the gallery via that which is why I reverted back to the existing date field. I was just asking/checking if this is more flexible in v11?

Are you saying you are ordering subgalleries by date but it won't accept any date in 1989? If so, what precisely is happening, is this it you cannot input it, is it an error before it lets you submit the form, is it an error from the server? What web browser is this?

Or are you saying there is no way to order subgalleries by date (which would be an entirely different issue to this one)?

Yes, I just can't hit the Submit button if I try adding a date in 1989, no linky no likey. Using Edge.

Okay I've checked. For this case, the rule is 20 years back. So the 2008 date in the original issue will work, but anything under 2002 will not work as of right now. I misspoke when I said 2000 works, it does not.

Yeah, this is bad. I don't think any real thought went into this +/- 20 year date range, other than:
1) originally we used HTML lists for date inputs and needed to limit the length of the lists for sanity reasons
2) we can't go before 1970 on all systems (it's an issue on Windows specifically, as it cannot deal with negative unix timestamps)
3) the year 2038 problem https://en.wikipedia.org/wiki/Year_2038_problem

I'm mulling it all over.