# It was Sunday on Jan 1, 2006. What was the day of the week Jan 1, 2010?

+1 vote
599 views
It was Sunday on Jan 1, 2006. What was the day of the week Jan 1, 2010?
posted Jul 8, 2016

If it's Sunday on January 1st 2006 then on January 1st 2010 it's Friday.

Jan 2006 - Jan 2007 = 365 days
Jan 2007 - Jan 2008 = 365 days
Jan 2008 - Jan 2009 = 366 days( It's a leap year )
Jan 2009 - Jan 2010 = 365 days.
Total days = 1461 days.

1456 is divisible by 7 (There are 7 days in a week ) so the remainder is +5 for 1461. Which implies Sunday + 5 days = Friday.

Taking into account that every four years, there is a leap year. Every normal new year Jan1 moves one day within the week, while for the leap year, Jan 1 moves two days within the week. Therefore, Jan 1 will move to say 3 + 2 days. Then, Jan1 in 2010 will be FRIDAY.

answer Jul 12, 2016 by anonymous

Similar Puzzles
–1 vote

Thinking about the treasure, the gringo forgot what day it was, so he asked four aborigines and got these answers:
A: Yesterday was Wednesday.
B: Tomorrow will be Sunday.
C: Today is Friday.
D: The day before yesterday was Thursday.
Because everything you need to know is how many people lied, I will not tell. What day of the week was it?

+1 vote

If I said that in three days' time it would be a Thursday, I am sure that most of you would have no difficulty telling me that today was a Monday.

Try this one then. Yesterday was two days before Monday. What day is it today? Yes, you're right again. It's Sunday. Do you get the idea?

Now let's tackle a similar question from The National Mathematics Contest (1991) Paper:

Three days ago, yesterday was the day before Sunday. What day will it be tomorrow?