# What are the little blue half-circles by the dates? **URL:** \ **Category:** Site Feedback\ **Created:** [February 8, 2024, 6:49pm UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318 "2024-02-08T18:49:41Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [February 8, 2024, 6:49pm UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/1 "2024-02-08T18:49:41Z")
Just started noticing this in the last few days. As I’m scrolling through a thread, a little blue half-circle appears by the date in each post, then fades away. It’s kind of distracting. What are they for? In Chrome on an Android phone, if that makes any difference. ---
**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\ **Post date:** [February 8, 2024, 6:53pm UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/2 "2024-02-08T18:53:39Z")
A WAG, they disappear when the system considers the post to have changed from _unread_ to _read_. ---
**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\ **Post date:** [February 8, 2024, 7:02pm UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/3 "2024-02-08T19:02:04Z")
Found it, > **[Did you know... (about Discourse)](https://www.sitepoint.com/community/t/did-you-know-about-discourse/96803/7)** > > Did you know… that Discourse tracks your readings? The little blue dot, next to the post number, (of which if you blink, will be gone), indicates an unread post. When the indicator fades away, it indicates Discourse considers the post... ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [February 8, 2024, 7:54pm UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/4 "2024-02-08T19:54:54Z")
Thanks. I kind of figured it was something like that, but wasn’t sure how that was different from the red “Last Visit” line in each thread. So, as an experiment, I opened a thread that had about 15 unread posts, and when it took me to where I had left off, I jumped all the way to the bottom, and I could see the blue mark on each post as I scrolled up. So I guess if you jump around in a thread, this will show posts you might have skipped over. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [February 8, 2024, 9:04pm UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/5 "2024-02-08T21:04:25Z")
They’re full circles here. Which half is missing for you? ---
**Author:** ![bobot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bobot/32/21622_2.png) [@bobot](https://boards.straightdope.com/u/bobot)\ **Post date:** [February 8, 2024, 9:39pm UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/6 "2024-02-08T21:39:42Z")
Man, I never noticed that before. But now… Now, there it is. There they are. Blue dots that fade away like someone who is looking at you does when you notice that they’re looking at you. ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [February 8, 2024, 9:49pm UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/7 "2024-02-08T21:49:55Z")
Upper right corner of each post above the date. Flat side to the right, round side to the left, like a little blue half moon. Could be because I’m on a mobile device that I’m not seeing the whole thing? ---
**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\ **Post date:** [February 8, 2024, 10:08pm UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/8 "2024-02-08T22:08:58Z")
Is the time/date obscuring the left half? ---
**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\ **Post date:** [February 8, 2024, 10:46pm UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/9 "2024-02-08T22:46:34Z")
The left half is what I see, it’s the right half that’s missing. The flat side is alongside the right side of the post box. It’s actually _above_ the date/time, all the way up in the corner. Nothing’s obscuring it. I’d try to get a screen shot if it didn’t disappear so fast! ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [February 8, 2024, 11:39pm UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/10 "2024-02-08T23:39:50Z")
You’ll also notice (at least on a non-phone) that at the same moment the url in the url bar updates to have the next post # on the end and the “##/##” display over on the right increments as well, and the scroll slider jumps at that time too. All of that is driven by the the background communications between client and server updating which post it thinks you’re actively looking at. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [February 9, 2024, 1:24am UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/11 "2024-02-09T01:24:36Z")
> [@bobot](#): > > Man, I never noticed that before That would probably be because it is new ---
**Author:** ![InternetLegend](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/internetlegend/32/13154_2.png) [@InternetLegend](https://boards.straightdope.com/u/InternetLegend)\ **Post date:** [February 9, 2024, 5:33am UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/12 "2024-02-09T05:33:29Z")
Well, I’m never _not_ going to notice it now! ---
**Author:** ![purplehorseshoe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/purplehorseshoe/32/2996_2.png) [@purplehorseshoe](https://boards.straightdope.com/u/purplehorseshoe)\ **Post date:** [February 9, 2024, 11:29am UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/13 "2024-02-09T11:29:56Z")
> [@Darren\_Garrison](#): > > They’re full circles here. Same for me. > [@bobot](#): > > fade away like someone who is looking at you does when you notice that they’re looking at you. I bet the Germans have a word for this phenomenon. ---
**Author:** ![BigT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bigt/32/12044_2.png) [@BigT](https://boards.straightdope.com/u/BigT)\ **Post date:** [February 11, 2024, 8:54pm UTC](https://boards.straightdope.com/t/what-are-the-little-blue-half-circles-by-the-dates/997318/14 "2024-02-11T20:54:40Z")
They’re half circles for me on mobile, because they appear at the right edge of the screen. If I scroll over, I see the other half.