Running shoes typically have a life in miles not time. The synthetics in the sole compress over time. How many miles depends on how you are using them, your weight and other factors. But typically, a pair of running shoes might be good for 300-500 miles of running before the sole material starts to fail. Something like a heavier hiking shoe might be 1000 miles. You have to be very careful taking advice here about durability as use matters. You wear them once a week to go for a light walk and they might last a long time. Wearing them daily when you are on your feet all day and they will not last as long. The only way to get shoes that last longer is by going with something that has less synthetics in it. But then you use the benefit of a modern shoe with the immediate comfort and support you get.