Aptitude - Calendar - Discussion

Feb is included(as we know a leap year contains 2 odd days, Here when we are going backward from 8th feb 2005 to 8th feb 2004,it includes the feb month ) i.e the correct answer is Sunday.

@Shwetank Verma is correct it is Monday.

Hear in 2004 feb 8.

There is no need to sub extra odd day before feb 28. Because, we haven't crossed the extra day of year.

So subtracting 1 is correct i.e., Monday.

I am not understanding, please explain to me, sir.

It there is any person who has understood the method correctly so please solve this one,

Q- what was the day on 20th april 1780 ?

Note - I need solution with method not only answer.

8th Feb, 2005 Tuesday.

We need to calculate 8th Feb, 2004 rite.

NOTE:

We need to understand that years like 2004, 2008, 2000 having 2 odd day because these are divisible by 4. The year not divisible by 4 is having 1 odd day only (simply means 2004, 2008, 2000 having 29 days in feb so total 366 days) (2001, 2002, 2003 like which are not div by 4 having only 28 day in feb so tot 365 days).

If you confused about odd day means just divide the total number of days by 7.

366/7 = 2 remainder so two odd days.

365/7 = 1 remainder so one odd day.

GOT IT:).

So let me come to our problem.

8th Feb, 2005:

So total days is.

Jan = 31.

Feb = till 8 so 31+8=39 is there in 2005.

8th Feb, 2004:

So calculate from 2004 8th feb to 2005 8th feb (we already calculate 39 days in the 2005 till feb).

Now 2004 feb contains 29 days we just need to calculate from 8th only.

Feb 8th to feb 29 = 21 days.

March = 31.

Apr = 30.

May = 31.

.
.

Dec=31.

Already we calculate the 2005 before it contains total of 39 days.

So add all these.

39 (2005's tot days because till feb means jan 31 day+ feb 8 day) +21 (2004 feb because from 8 to 29 only need) +31 (mar 2004) +30 (apr 2004) +...+31 (dec) = 366.

Now 366/7 = 2 days remainder.

0 1 2 3 4 5 6.

S m t w t f s.

2005 feb 8 is Tuesday.

Now need 2004 feb 8. Here calculate from higher to lower year so just minus the reminder 366/7 = 2 from Tuesday.

SO SUNDAY.

Hey this takes quite a long time to find days of week like this. But competitive exams does not provide us such a long time. Please suggest me something.

Same calender repeats if it is.
1) leap year=+28yrs.
2) leap+1 year=+6yrs.
3) leap+2years=+11yrs.
4) leap+3year=+11yrs.
For exa. -.
1984=leap year.
Same calender repeats on 2012.

How we know that year is leap or not ?

8+2+4+1-1=14/7

Remainder=0
Sunday.

I can't understand using formula.