Why did a lawyer who is a notary public put date on some affidavits and not others?

I received notification from a lawyer about pending case. He affixed notary stamp. There is no date on stamp and on some affidavits, he put only the month and year, but no date. Are these papers legal?

If the dates left off are on the notary stamp,the notarization is invalid. That doesn't mean the document itself is not valid.

If the dates are left off of the document, that might be a problem, but it depends on what dates were left blank and why. It could be they don't know the exact date yet and that will be added.

Generally if there is such a problem in a legal document, you can challenge it, but then the judge will usually give them a chance to fix it.

If this is your attorney, ask him. If you are being sued you should get an attorney. Depending on what the suit is for (if that's what the papers are about) your insurance company may provide a lawyer if you have one.