Vulnerability Date - Published, Added, Modified

Hello everyone
I have a quick question about the three different dates of a vulnerability. Published means the official date when this vulnerability was made public or CVE.

Modified means that the corresponding vulnerability information has been updated.

Now to my question. Does ADDED mean the date when the vulnerability can be found with a scan?
I have seen cases where the published date is several months before the ADDED date.

I just want to create a new metric in our reports and PowerBI dashboard where I can categorize vulnerabilities.

Best regards