"Over" and "for" is not the issue. Nor is days/weeks/centuries... The same rule applies.
Originally Posted by moonlike
Now, in post #3, you said "
I already know this one "The previous century" depends on what is given as the base century."
But then you make the illogical leap to assuming
So you mean here just "over the previous few days"is right?"
No, I meant "Only 'over the last few days' is right". Why should "the previous few days" not depend on the base day just the same as "the previous century"? (It does). "Previous" requires mention of a base time. For "last", the base time is now.
There should be no more explaining necessary if you read the thread carefully again.