Life can get busy! Sometimes you need to schedule a video to post in advance. Through the upload scheduling feature within YouTube, you're able to set a private video to go public at a specific time.
Sign in to YouTube Studio
In the top-right, click 'Create' then 'Upload Video'
Select the file that you'd like to upload and enter your video details
On the “Visibility” tab, select Schedule
Set the date, time, and time zone that you want your video to be published
Click 'Schedule'
Until the date and time you selected, the video you uploaded will remain 'Private' and will not be viewable to the public.