Reston, Va. -- For the holiday season-to-date (Nov. 1 - 24), $18.9 billion has been spent online using desktop computers, up 14% versus the corresponding days last year, according to comScore. Tuesday, November 19 was the heaviest online spending day of the season to date at $963 million. Two other shopping days – Thursday, Nov. 14 and Sunday, Nov. 24 – have also seen at least $900 million in online retail spending.