Sitemap.xml uses invalid datetime separator

[JMalaprade]

Noticed that sitemap.xml returns "invalid date" errors in a Google Console's sitemap verification tool. I believe this happens because the sitemap uses a wrong datetime separator: dots instead of colons.

Example of the current situation:
<url> <loc> https://www.domain.fi/somehting </loc> <lastmod>2023-11-27T06.07.36+00:00</lastmod> <changefreq>daily</changefreq> <priority>0.5</priority> </url>

That should be (YYYY-MM-DDThh:mm:ss.sTZD):
<url> <loc> https://www.domain.fi/somehting </loc> <lastmod>2023-11-27T06:07:36+00:00</lastmod> <changefreq>daily</changefreq> <priority>0.5</priority> </url>

[MikeAlhayek]

@JMalaprade what version are you using?

Looking at the code briefly, seems that we are using the correct format

OrchardCore/src/OrchardCore.Modules/OrchardCore.Contents/Sitemaps/ContentTypesSitemapSourceBuilder.cs

Line 165 in b23ec3e

lastMod.Add(contentItem.ModifiedUtc.GetValueOrDefault().ToString("yyyy-MM-ddTHH:mm:sszzz"));

and

OrchardCore/src/OrchardCore.Modules/OrchardCore.Sitemaps/Builders/CustomPathSitemapSourceBuilder.cs

Line 72 in b23ec3e

lastMod.Add(source.LastUpdate.GetValueOrDefault().ToString("yyyy-MM-ddTHH:mm:sszzz", CultureInfo.InvariantCulture));

[sebastienros]

@MikeAlhayek the first sample you point to is missing CultureInfo.InvariantCulture. Without it it will use the local culture, which is the issue that is described.

[MikeAlhayek]

uh! I missed that. good catch