The chronology of both פרשת נח and פרשת בראשית are significant in understanding the age of the world. There were twenty generations from Adam to Abraham.
The Kuzari adds an additional point that only the sons mentioned in the Torah, were righteous. Usually, there was only one good one in every family until Yakov Avinu came along where all of his children were pious. This family was chosen to become עם ישראל.
Rabbeinu Bechaye also emphasized the importance of knowing important dates. He points out that Avraham was נח (58) years old when נח died. So even though twenty generations passed, Avraham knew Noach who knew Metushelach who knew Adam.
The other two dates that are important to remember is that Avraham was born 1948 years after creation. And the year of our exodus from Egypt was in the year 2448.
All of these dates come together when we combine them with other events. Two such examples are the rise to power of Alexander the Great exactly 1000 years after leaving Egypt and receiving the Torah. And Chazal tell us that prophecy existed for 1000 years which corresponded to forty years into the second Temple period. This probably was the same time as the famous meeting between Alexander the Great and the Kohein Gadol, Shimon Hatzaddik.
Dates are extremely important as they help verify the truth of the Torah and Judaism.