fourcheesecalzone asked:
Sometimes, on the app, when I see a post from a blog that has been deleted, it will still show the date it was made, whereas on desktop the same post will not show the date. I find it very helpful to see the date on a post even if the blog doesn't exist anymore. Is there a reason Tumblr doesn't show the date when it apparently still has that information?
Answer: Hey, @fourcheesecalzone!
First, a long story short. We didn’t start recording this timestamp in reblog trails until ~3 years ago, so any reblogs from before that time may not have the information in the trail. We do our best to “backfill” the timestamp, but in cases where the post or blog was deleted, we don’t have anything to look up, so we can’t backfill it.
And now a little longer version. Reblogs store copies of the previous items in the reblog trail. So if I make a post, and then you reblog it, your reblog has a copy of my post content. This leads to some fun things: like if I edit my post, your reblog of it won’t be updated, and if someone clicks the original post in your reblog, they’ll see a new post. Fun! We did this to increase the performance of the whole platform. It means we don’t have to look up every post in the reblog trail, which can be dozens to hundreds of posts long.
Unfortunately, it also means things like what you’re describing can happen. If we make a change to what we’re storing in the reblog trail (like we did with NPF in ~2017), it’s incredibly difficult for us to update the tens of billions of posts on Tumblr. Recording timestamps in reblog trails is a very similar problem. It would take us years to go through each reblog across Tumblr to update them, and we don’t feel like it’s that big of a deal for it to be sometimes missing.
Thanks for getting in touch, and we hope this clarifies things.
