This started with a simple question: when exactly did I write that? LinkedIn's own timestamps are vague at best and drift into "a while ago" fairly quickly, which is not particularly useful if you want to know the precise date of something you posted a while back. So I went digging, and it turns out the answer was sitting in the URL the whole time.
LinkedIn uses a Snowflake ID system, which means every post, comment, and reply carries a 19-digit ID with the creation timestamp baked directly into it. A bitwise right shift of 22 positions strips away the internal bits and leaves you with the exact millisecond it was created. Once you know that, building a tool around it is fairly straightforward.
Paste a LinkedIn URL into the tool and it will extract the exact date and time of the original post, any comment the URL points to, and any reply to that comment. It also shows the time gap between each event, which turns out to be quite revealing in certain contexts. All times are shown in your chosen timezone as well as UTC, and the dropdown defaults to your local timezone automatically.
The whole thing is a single HTML file with no dependencies and no server. Everything runs in the browser and nothing is sent anywhere.