Most definitely. If you sow them too early, your plants can become root bound, requiring another transplanting step into larger pots (more work), or they can become large and leggy, making them more difficult to transplant and, typically, more fragile and susceptible to wind damage. Starting your plants too late runs the risk of running out of growing season before the fruit ripens.
On our farm, we typically begin sowing our tomatoes about six weeks before the day we expect to plant them in the garden. Although you can never know exactly when your last frost of the winter/spring season will be, we can use averages of historical data to make educated guesses. Folks in the United States can find this information here and Canadian gardeners can find it here.