Will changing URLs with .htaccess impact my SEO negatively?

Question

Basically, I have URL like www.example.com/month/day/name-of-post. What I want to do is to change the month/day to blog/month (or just /blog/) for continuity.

I have a WordPress and the pages are decently ranked, so I don't want to create a new one. So I came up with a .htaccess change of the name.

When I change the expression of the URL, will it impact my current SEO position negatively? Do I have to change it in sitemap.xml as well? Or should I just leave it be?

PS: Didn't try anything yet, don't want to negatively impact my SEO with this, so asking first.
PPS: I tried to find similar question, but they were different in some way.

Answer 1

If you are proposing to leave the ranked pages' URL alone as they appear to public, then it won't have an impact on your SEO rankings. SEO won't know any different. That is you are doing a rewrite instead of a redirect. See Rewrite vs Redirect

If you want to change the URL publicly as well, then you can do it in two ways.

1. Provide redirections from the old URL to the new URL. Ensure the canonical is the new URL.
2. Have both URLS available to the public and make the canonical the new URL.

Regarding the sitemap, if you are using rewrite to just change the internal structure, then the sitemap requires no change.

If, however, you are changing the publicly viewable URLs then my opinion is to leave both the new and the old URLs in until the next crawl. After that, you can remove the old ones.