In ten years time / in ten years' time ??

Witam!

In ten years time - znaczy - za dziesięć lat.

Zauważam, że dosyć często w tekstach raz jest napisane np. "in ten years time", a raz "in ten years' time". Jaka jest różnica pomiędzy tymi dwoma zwrotami? Jaką fukncję spełnia apostrof? W tłumaczeniach na język polski oby dwa zwroty znaczą to samo.

Pozdrawiam,
Łukasz

I may be wrong, but I believe "ten years time" is correct. The apostrophe indicates a possessive of the plural form.

Example: Dog's breakfast: sniadanie psa (jednego)
Dogs' breakfasts: sniadania psow (wielu)

Since in the phrase is meant to express duration (a period lasting ten years), the apostrophe is incorrect. Putting the apostrophe would mean that the "time" belongs to "ten years", which is nonsensical.

Be that as it may, I consider "XXX years time", or "XXX days time", an inelegant expression due to the redundancy: year , days, whatever, IS time. Better to say: in ten years, over 10 years, or over a period of 10 years, and forget about the "time".

I wouldn't go so far as to criticise "ten years' time" as incorrect. "A time of ten years" is definitely correct and consequently the Saxon genitive appears legitimate here. That said, your interpretation is interesting.
In a nutshell, both phrases are correct.

The apostrophe should be there in ten years' time, ten years' experience...
If it is not there, the omission is common negligence.

negligence? i wouldn't go that far! it's def'tley incorrect w/o the apostrophe, but you will see many people do that... after all, not everyone can a spelling bee champ :(

>but you will see many people do that...

Yes, sir.
That's why I called it common negligence (ordinary, usual, widespread failure to take proper care)