How do I breed garden snails?

As of posting, I have two adult, healthy, Garden Snails whom I made a mini terrarium to breed in. I hope to have a bunch of snails as a result! I just wonder if the conditions are adequate and how long breeding and how long maturing of the eggs will take. I placed the two snails (which belong to my mother) in a mini terrarium with moist soil, a lot of bokchoy, and egg shells, in a warm and wet environment.