Rule: Some it time adverbials is emphatic; with count nouns it means 'quite a few', not 'a few'.
Examples of errors:
(1) Some days ago I decided to go on a trip.
(2) He certainly lost consciousness for some time.
(3) One explanation for the attraction of Fasching is that some people want to be a different person for some time.
(4) I think it's better to wait some weeks more and buy them when they go on sale after Christmas.
(5) Sometimes we just have some minutes to get from one class to another.
(6) What did I do at Christmas? This year I went home to my parents for some days.
(7) I'm very busy and don't read a lot. I don't have enough time to concentrate on a book for some days or even a week.
(8) Then I returned to Kassel to spend some days just being lazy.
(9) You probably can't imagine that it has already taken me some quarters of an hour just to think of an appropriate subject to talk about.
(10) We found a steep hill that was perfect for sledding. We did it some times, and then it became boring.
(11) Another sport I like is horseback riding. In fact, for some years when I was working in an office we had a horse.
(12) The biggest accident ever to occur in a nuclear installation happened some weeks ago.
Some days ago (cf. (1)) doesn't mean 'a few days ago'(vor einige Tagen) but 'quite a few days ago'. For some time (cf. (2)-(3)) doesn't mean 'for a while' but 'for quite a while'. When some does occur in such time adverbials, it receives full stress, whereas otherwise it is normally unstressed; compare:
I thought about your proposal for sóme weeks (i.e. for quite a few weeks).
I bought some books today (i.e. a few books).
In (l)-(12) the intended meaning is that of (unemphatic) unstressed some, but this some doesn't normally occur in time adverbials:
I bought some books
*I walked for some hours
Some occurs unstressed in
Give me some time to think about it
but here some time is the direct object.-not a time adverbial. By comparison, one does not say
*I thought about it for some time