add date post update - MOBILE

Hi there,

you can try this:

/* Move Dates below Author on wider screen */
@media (max-width: 1024px) {
    .entry-header .entry-meta {
        flex-direction: column;
    }
}

/* Stack all elements in one column on smaller screen */
@media (max-width: 768px) {
    .entry-header .entry-meta .posted-on a {
        display: inline-flex;
        flex-direction: column;
    }
}

Thank you David

I would like to tell the search engines when the article is updated.

How can I integrate the information into the "markup scheme"?

You site contains the Date Meta so Search Engines will see the two dates. What they do with them is out of control.
General rule for Google it will use display an updated date IF it sees a relevant update has been made. This is to stop people from just updating the dates to get better ranking