How to properly format last modified (lastmod) time for xml sitemaps

Question

I am creating an app that will automatically update sitemap.xml each time new content is added to, or updated on the site.

According to Google\'s best pract

Answer 1

Properly format last modified (lastmod) time for XML sitemaps in C#

var ss = DateTime.Now.ToString("yyyy-mm-ddThh:mm:ss:zzz");