One of the lettuce varieties I grew this past summer was called red salad bowl. It is a leaf lettuce instead of a head lettuce so ensures that it crops a lot of lettuce over a long period of time.
Below are the days to maturity for red salad bowl lettuce. Being in Australia they are written in the format of Day/Month/Year.
Days to Maturity Red Salad Bowl Lettuce (Lactuca sativa)
Planted 23/10/2016 Day 0
Germinated 28/10/2016 Day 5
Started harvesting 03/12/2016 Day 41