What was the day of the week on 28th May, 2006?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Sunday
The weekday of a date is fixed by the number of odd days (days left over after whole weeks) from the start of the calendar up to that date: 0 odd days is Sunday, 1 is Monday, 2 is Tuesday, and so on. An ordinary year has 1 odd day and a leap year 2.
The 2005 complete years:
First 2000 years: 0 odd days (every block of 400 years has 0)
2001 to 2005: 4 ordinary years and 1 leap year (2004), so \(4\times1+1\times2=6\) odd days
1 January to 28 May 2006:
Days \(=31+28+31+30+28=148\)
\(148=21\) weeks + 1 day, so 1 odd day
Total: \(0+6+1=7\) odd days, which is one whole week, that is, 0 odd days. So 28 May 2006 was a Sunday.