I have a specific page with a table having some important information that is updated by employees every one hour , I want to let the google know that this page is updated faster than any other similar tables on the other sites . I want inform google that this page has not any publish date , It's dynamic and live , So how can I do this?
If you really want the page to be updated in search engine caches as often as possible, in your sitemap, specify
changefreq of the page to be
hourly. This tells search engines that the page will be updated every hour.
They may not honor the request if your page has low authority, but that's how you ask them.
More info: https://www.sitemaps.org/protocol.html
Maximillian has pretty much hit this on the head. I would however say you don't want to suggest there are edits more frequently than there actually is. The timestamp is used so that the crawler can say 'when was this last updated?' - That matches the date we already have therefore skip this file. - if not, let do a crawl.
I read somewhere (so probably not 100% trustworthy) that each site is allocated an amount of pages a spider can crawl (in one go). So, if you're constantly saying that content has changed, you're wasting this 'credit' on already crawled pages. If it visits and can see that however many pages have already been crawled it can move on to the ones that still need adding / ones that have changes.
Again, I cannot find this source of information. But, it would make sense considering there are now a stupid amount of pages on the web.