You can set your date of birth, this is probably the most important setting for a life calendar. Otherwise, you will be viewing incorrect data.
An interesting fact is that in medieval Europe, life expectancy ranged from 30 to 40 years. However, it is worth noting that these data reflect life expectancy, which has been significantly reduced due to high infant mortality. If a person lived to adulthood, their chances for a longer life increased. With the improvement of living conditions, the development of medicine, sanitation, food security and other factors in the 20th century and later, life expectancy has increased significantly. Today, in many countries, the average life expectancy is over 70-80 years, and in some cases even exceeds 80-90 years