Since 2004 was a leap year, the number of days from 8th February, 2004 to 8th February, 2005 is 366 days. To find the day of the week, we calculate the remainder when 366 is divided by 7:
\[ 366 \div 7 = 52 \, \text{weeks and 2 extra days} \]
Thus, the day on 8th February, 2004 was two days before Tuesday, which is Sunday.
If it was a Friday on 15th September 2023, then what will be the day on 20th September 2024?