Also business casual does not allow Jeans (even w/o a suit).
Where I work, jeans are acceptable business casual wear in certain departments (such as mine). The reason this is allowed is so that when you are called out to the field (power plants, steam plants, substations etc) that you can still go without changing much (just changing into safety shoes).
SJSinNYC, of course on shabbos you should dress more formally than during the week. So on shabbos wear a suit, and during the week wear dress shirt/pants (assuming you’re male). However, you still shouldn’t be dressed informally when davening during the week.
Where I live, many men come to shul in khakis and a sports jacket on Shabbos. They will show up to shul in jeans, because its what they wear. I don’t have a problem with it, so long as the jeans arent the ripped/torn ratty looking ones. I do understand that others want to always be more formal, which is fine, but sometimes what I see men wearing to shul (although the material may not be denim) is the same level of casualness as jeans, just in a different color (for example, casual black pants).
Jeans are goyish – some denim skirts are also. But, as there are so many other materials available why go for denim if you know it’s not appropriate? As I said if you want to wear jeans – fine wear them because you like them but don’t say they are appropriate attire – cos they’re not.
Please clarify – is it the material that is goyish or the style of pants? If its the material, then no jean skirts would be ok for women.
I have no problem if you think that you wouldnt wear them, but calling saying they are inappropriate attire across the board (IMHO) is a misnomer.
Jeans have become a symbolic form of clothing of “Hey, I’m really cool in how I dress, I’m in with the in crowd”
In certain crowds this is true (and Itzik referenced this nicely above), but in my community jeans are normal attire. So wearing them is not a statement in any way. Walking into a yeshivish shul in jeans may be (depending on the situation) making a statement.