Didn't you READ the article? The date of conception was late March and nine months later is late December. We do NOT "need" a Biblical command to celebrate the birth of the Lamb of God. Saturnalia is NOT the basis for Christmas any more than Baccanalia is the basis for Easter. Easter is tied somewhat to Passover because the Last Supper was the Pesach or Seder meal on the first night of Passover which is why they had to bury Him in haste.
Ray from Bloombergia
Soli Deo Gloria!!