How does delayed posting work on social networks?

Question

Social media

Interested in the question of how deferred posting services are implemented, which make it possible to specify the time up to a minute. There, in fact, every minute they run a task in the crown, which checks the timers and gives commands to publish, or is everything done somehow differently?

Answer 1

How exactly it is implemented I will not say. But if I created something similar, I would make it easier. All posts are logged as regular posts, but there is an additional "Post Time" field, which defaults to "Now". But this time can be set in the future up to a second.
And the script that displays messages simply displays all messages whose "publish time" is less than the current time. Thus, posts for which the publication time has not yet come will not be displayed.
In this case, sorting is carried out not by ID, but just by "Publication time", then the message written a week ago will appear above the rest.

Answer 2

Cron is not required.
It may well be a sheduler program running all the time. She launches publications up to a second

Answer 3

Ambassador in the job list you throw a task on time, this is in almost all programming languages