1. Start a free Dropbox account, create a public upload folder and share said upload link with everyone in the group. 2. Start a throw-away Gmail account, schedule an email containing the username and password to the Dropbox folder to all of the club users for a future date, X weeks in the future. 3. Logout of the dropbox and Google account, throw away the passwords to both.
As long as the email from the throw-away gmail account goes through, then everyone gets the time-capsuled password to Dropbox at the same time and can then log-in to Dropbox at their leisure to view the documents.
Obviously this solution is for a small, very-trusted group and doesn't scale, and has other security problems and the risk of losing everything.
Edit: Also found this, a bit old-school, Windows-based, PC-based solution, not really a modern tool designed to work over the web/internet it seems. https://www.jensscheffler.de/filelocker
There also appears to be a standard way of locking files in bash, which could be used to cobble together a solution where perhaps a file could be maybe scp'd into a server, locked upon upload, and then perhaps the directory unlocked at a pre-determined date for all users, but that seems like it would require a lot of thinking and building and sys-admin manual labor. https://stackoverflow.com/questions/1715137/what-is-the-best...