Sunday
Thursday
Tuesday
Step 1: Use year-shift rule.
2006 is a non-leap year. The same date next year shifts by \(+1\) weekday.
So \(8\) Dec \(2006 \xrightarrow{+365\ \text{days}} 8\) Dec \(2007\) is \(+1\) day.
Step 2: Work backward from 2007.
If \(8\) Dec \(2007\) is Saturday, then \(8\) Dec \(2006\) was one day earlier: \(\boxed{\text{Friday}}\).
If it was a Friday on 15th September 2023, then what will be the day on 20th September 2024?