Reminders in themselves are nothing amazing, Apples reminder app is location based and therefore has capabilities to remind when arriving or leaving a specific location.
So an example would be to put my gym bag into the car when i get home so I don't forget tomorrow, or a reminder to take my lunchbox home when I leave work.
Open the reminders app click + and type in your reminder
On a Day will apply to a specific date and At a Location will apply to the location and when I leave or When I Arrive