I used to put exact time/date information into tooltips, thinking "the users that need it can find it without overloading the UI". I ended up undoing a lot of that a few years later when user interviews demonstrated that hyperlink-style underlines was insufficient for users to think "mouse over this".

With the prevalence of emoji and higher resolution displays, I wonder if tooltip hinting with an obnoxious question-mark or magnifying-glass image would be sufficient to hint to older/less-savvy users.