This LinkedIn post date extractor tool reads the date from the link itself. Every post link carries a long number, the post ID, and its first part is the moment the post was created, as a Unix timestamp in milliseconds. Paste one link or a whole list and each time comes back, newest first. The math runs in your browser, and nothing is sent to LinkedIn or to us.
How to read the result
Each post gets one line: the time in your own time zone and in UTC, its age in days, and whether it falls inside the freshness window you pick. Change the window and every line is marked again, without pasting anything twice.
A comment link carries two IDs, the post's and the comment's, so you get both dates. A link pasted twice is counted once. Lines with no post ID are set aside with the reason.
You can copy the list into a spreadsheet or download it as a file. Both keep the newest-first order, not your paste order, so match on the link when you put the dates back beside your own list.
Where the date can read early
The ID is written when the post is created, and a post can be created before it goes live. In our check against the published time LinkedIn shows on public posts, activity IDs matched. Share and ugcPost IDs came out earlier, by minutes in one case and hours in another. Read those as "created by", not "went live at".
The method is public. An open-source extractor on GitHub documents it, and LinkedIn's developer documentation on URNs explains the identifiers in post links. We use the method, not anyone's code.
What to do next
Sort the posts you saved and write first to the authors whose posts are fresh. A comment on last week's post reads as attention. The same line on last year's reads as a mail merge.
Finding who is writing about your topic now is the step before. In Oneprofile that is a people search on the phrases your buyers use, and each person comes with their newest matching post and its date. How to find leads on LinkedIn walks through it.