Sale has ended but you can still get this app.
Download Long-Term Calendar Reminders Now
Long-Term Calendar Reminders

Official Description

With a single tap add reminders to your calendar days, weeks, months, or years in the future. Your calendar app (such as google calendar) will be responsible for sending the reminder when the event occurs so there's no overhead to using this app, you could even uninstall it and your reminders will still be saved in your calendar.

Compatible with any standard android calendar system. All this app does is open the create event window for your calendar app, set to a specific point in the future.