You can now schedule a LinkedIn post directly on LinkedIn.  You used to be able to do this on 3rd party tools like Buffer or Hootsuite but now you can do it when you are posting on LinkedIn.

Instructions (with images below):

1. Click Start a post at the top of your LinkedIn homepage. The Create a Post window will appear.
2. Type the content of your post in the "What do you want to talk about?" field.
3. Click the Clock icon in the lower-right corner to schedule your post.
4. In the Schedule post-pop-up window, select a date and time when you want to publish the post. The time selected must be within 1 hour to 3 months from the current time 
5. Note: Scheduled time will be standardized in UTC based on your device's time zone settings.
6. Click Next.
7. You can see the scheduled date and time above the post.
8. Click Schedule.

A post-scheduled confirmation pop-up appears on the lower left of the page.

You can do this on your mobile too.  Worth an explore if you have an event to announce or want to make sure a post appears at a specific time in a particular time zone.

Not sure this is 100% universal but everyone I have talked to can see it.  If you cannot then you will be able to soon.