Winter or winter's day?

Winter. It's an adjective.

Both are used, but the second is rarer and has a more poetic feel to it. Think "California Dreamin'".

The Mamas and the Papas were throwing me off, too, but Ray's right!

Off to download that song...

Could always go with wintry. More clearly an adjective in my mind.

Winter can't really "possess" anything, so if you did you use the second option, it would be "winters day".

I think.

No, it would be the possessive. A door doesn't possess a colour, but we would still write it "the door's colour was a vivid blue".

Possessive is attributed to human if I'm not mistaken. "The man's shirt", however, "a car door". Exceptions apply.

But, here ,winter is an adjective, not a noun.

Well, there goes the possessive adjective "its". It refers to possession by non-human things, so I guess it's breaking the rule...

The tree stood stark against the sky, its branches dripping in the rain.

Jesus! It's more controversial than I thought. Look what I dug up.

Many writers consider it bad form to use apostrophe -s possessives with pieces of furniture and buildings or inanimate objects in general. Instead of "the desk's edge" (according to many authorities), we should write "the edge of the desk" and instead of "the hotel's windows" we should write "the windows of the hotel." In fact, we would probably avoid the possessive altogether and use the noun as an attributive: "the hotel windows." This rule (if, in fact, it is one) is no longer universally endorsed. We would not say "the radio of that car" instead of "that car's radio" (or the "car radio") and we would not write "the desire of my heart" instead of "my heart's desire." Writing "the edge of the ski" would probably be an improvement over "the ski's edge," however.

For expressions of time and measurement, the possessive is shown with an apostrophe -s: "one dollar's worth," "two dollars' worth," "a hard day's night," "two years' experience," "an evening's entertainment," and "two weeks' notice" (the title of the Hollywood movie nothwithstanding).

Bad form and incorrect grammar are not the same thing. Personally, I think "some writers" are getting carried away with the thrill of making rules. And I suspect it stems from the fact that some ancient grammarian chose the label "possessive" to describe a linguistic phenomenon and people are trying to retrofit the language to the label.

Isn't bad form worse than incorrect grammar? and good form transcendent to correct grammar, especially, if one aims to entice the readers? Then, again, there's no standard, but standards.

For christ sake, I just can't write today .

In general, Eryl, I would agree. But I honestly find this particular quibble a little silly. How many of us have ever said to ourselves, "Oh my! This writer just said 'the tree's branches' instead of 'the branches of the tree'. I think I'll throw the book across the room."

I didn't think so. Both are perfectly acceptable English and I would probably make the choice between the two as a function of rhythm and style as much as anything else. It's like arguing whether chocolate or vanilla ice cream is better.

I love grammar. I love an elegant, well-turned phrase. I like consistent rules that work and that are based on the actual structure of the language. I do not like people inventing rules that have more to do with snobbism than functionality or beauty or elegance or anything of inherent value.

I dislike bad grammar because it's inconsistent and illogical and often makes the text difficult to understand. Some grammatical rules are illogical, but they are the accepted usage so I put up with them. I cheer when they die. For instance, making the plural of a family name by using an apostrophe is no longer a hard and fast rule. It is going the way of the dodo. Good riddance. It was a stupid rule that created no end of confusion.

Rant over.

ETA: In case this isn't perfectly clear, I am not taking shots at you personally by any means. This is an abstract rant. If that makes any sense.

Well said!

Possessive

I don't know about bad form, but good grammar says many things can claim a possessive. Days, weeks, months, years, seasons, and darned near anything else there is can have a possessive.