Fabrice Canel from Microsoft said that Microsoft tries to check your site's XML Sitemap file one per day. He said on Twitter "we attempt looking at sitemaps once a day."
Fabrice added that "Sitemaps is a great way to tell search engines all the relevant URLs on your site."
But if you don't want to wait for Bing to index your URLs, he recommends you use the new IndexNow protocol or Bing URL submission API. "Do you like to wait 2+ days to see your content indexed? IndexNow https://indexnow.org allows you to have your content index now, not in few days," Fabrice explained.
Here is that tweet:
Sitemaps is a great way to tell search engines all the relevant URLs on your site. We attempt looking at sitemaps once a day. Do you like to wait 2+ days to see your content indexed? IndexNow https://t.co/glgkf4OfsG allows you to have your content index now, not in few days.
— Fabrice Canel (@facan) October 18, 2021
Google doesn't necessarily access your Sitemap file daily, I believe it does it based on how frequently you change the file. I asked John if this changed at all, and he said no...
It's algorithmic - some files never change, some change frequently. Also, the ping-functionality is a good way to let us know about changes. (And, not all sitemaps lead to useful / relevant / high-quality content, unfortunately)
— 🧀 John 🧀 (@JohnMu) October 19, 2021
Forum discussion at Twitter.