I know that most people seem to use the infinite scroll on their tumblr dashboard, and I believe that's the only option on mobile, however, I like to use page view, which gives me one dumb quirk that I like to exploit
Page view's url gives me this, and the post id correlates to a time stamp. When I go to the next page, the number goes down, and it shows me the next 10 or so posts.
Click on the 3 dots and you can see the time stamp of when it was reblogged/posted
However, if I change the numbers in the url
I can go back in time
And the lower the number, the farther I go
Even back to the dark ages
