Are you using ServiceDesk / ITBM or Helpdesk / SupportCentre? If ServiceDesk / ITBM then you can do this by setting up mailmanager to be able to create tickets from incoming emails to a certain inbox to a certain change process (if you haven't already got this setup). Then it's just a case of scheduling that an email gets sent to that particular inbox each time you want a new change to be raised. Depending on your mail client you can have various ways of setting up a scheduled email - searching online for advice should give you some good ways to achieve this.
We are using Service Desk with Mail Manager. This is a great solution, thank you!
If you are on 7.3 you could have a single 'patch'process which gets woken up every month by a scheduled action.