Are there any good or bad days to consider when planning a wedding? If there are bad days how can I find out?

There aren't any
Pick a day that has special meaning or is a favorite time for you.
Like my favorite month is July, may favorite day is the 4th. But many days in the summer have special meaning to me. Even August the 13th Friday --Alfred Hitchcocks birthday. Twice ended up with something special in the day for me.
Or you could pick a day that is generally boring to give it some meaning.

Personally, me living in the cold climate when it rains a good bit I would pick a day that was most likely going to be 80 degrees and sunny.

The day your divorce is final from a past marriage is often in bad taste

The day your divorce is final from a past marriage is often in bad tasteActually that might be kind of funny! If I ever remarry I just might consider it!

We get a lot of those questions in the legal area, what time of day can we get married.

Or perhaps the date of your first wedding, so you can remember the date better.

Astrologers can sometimes advise you regarding the best date for a wedding, based on the 'birth date' of your relationship i.e. the date that you met.