Which resource allows you to leave notes that can be opened no earlier than a certain time?

Question

Computer networks

Task and conditions:
There is a test information is not large. It is necessary to lay it out, conditionally at 12 days, and so that the resource on which it is posted must display information when the file / text actually appeared there without the possibility of falsifying this item, but the opportunity to read / watch it appeared no earlier than the time indicated by the uploader. Something like a private message is only possible without self-destruction and with the download date. Thank you.

Answer 1

blogger
livejournal

Answer 2

There is a delayed publication function in VKontakte.
Set the time when the post should appear (for example, in a group) and it will be published at the right time