Welcome banner copyright date

From what was said about copyright dates by Steve Revill in an old thread, any copyright message should show the date when it was first published. If it is updated, then it may also show the range to the updated date.

However, the dates on the welcome banner splash screen that are shown when some versions of RISC OS boot (eg Iyonix) do not now abide by this. Since soon after v5.18 the Desktop module was changed to avoid updating it for every release, and it inserts the current year from the OS version string given by OS_Byte,0,0 into the string to be displayed to show
© <current> Castle Technology Ltd.

Should this be changed to
© 2002-<current> Castle Technology Ltd.

Given copyright is the life of the author (what does this mean when a company is the author?) plus 70 years (EU/US; 50 years CA/AUS), and given the copyright claim goes from the first date given, not the last… is there any particular benefit to adding a second date?

That said, a huge amount of the codebase comes from Acorn’s versions of RISC OS, dating back to Arthur. Shouldn’t, therefore, the proper copyright look more like “© 1986 Acorn Computers Ltd; © 2002 Castle Technology Ltd.”?

given the copyright claim goes from the first date given,

Expression of copyright from the date of the owner first publishing that specific version

Now consider that if you are updating and re-issuing then each new version has a new start date.

Acorn Computers Ltd no longer exists and all rights to the OS have been purchased through Pace by Castle Technology Ltd. RISCOS Ltd did not fully own RISC OS when it issued RISC OS 4 and therefore had to mention the other copyright holder. That is why Pace is also on the start screen of RISC OS 4. RISCOS Ltd did not have all the rights when it issued RISC OS 6, or was not sure who had the other rights, so they, to be safe, mentioned Acorn.

Expression of copyright from the date of the owner first publishing that specific version

There is a school of thought that updates to existing things should retain the original year of first publication (as it is an update, not something new).

There is also a school of thought that having a recent year (2018) makes it unclear that you would be claiming previous rights (say, 2008…). Seems a bit bogus to me as a release in 2008 would say 2008, but then legal stuff is mostly applied bogosity as far as I’m concerned…

RISCOS Ltd did not have all the rights when it issued RISC OS 6, or was not sure who had the other rights, so they, to be safe, mentioned Acorn.

There’s a school of thought¹ that says ROL knew the answer but to muddy the waters they mentioned the original rather than the extant owners of the other rights. Hey, ho, history…

is there any particular benefit to adding a second date?

Potentially, yes, in the event of disputes arising about ownership of copyright. If someone claims that their copyright predates yours, and they can show an older version of your work without some feature you added later, they can cast doubt on the validity of your claims.