The Best User Interfaces Require No Math: Simplifying Time Display
the best user interfaces require no math.
when dealing with time, you don't want your users to calculate how long ago a post was made.
generally, if a post was made today, it would help to know if it was xx many hours ago or xx seconds ago.
as the post gets older and decreases in relevancy, you can abstract that information in a decreasing order of specificity.
if you use facebook or instagram, you know what i'm talking about. here's an angular pipe that does just that.
you could modify this pipe to show the exact date if the content was greater than 1 week old. you could also add the actual date on hover.