Oddi resumed his work in the Oddatala where he stated the position of the sun for every day of the year in Iceland and calculated the date of summer and winter solstices and their direction giving a useful source of orientation for sailors, since no navigational instruments were used at that time.
The first chapter presents the exact date and time of summer and winter solstices with relation to the leap years.
[1] In the eleventh and twelfth century the Julian calendar was introduced; it had to be adjusted to local parameters.
Star Oddi's observations made a significant contribution to correctly adapting the Christian calendar.
After Oddi's time the role of local, first hand scientific observations lost more and more importance due to growing literacy and acquirement of knowledge from books.