Aptitude - Calendar - Discussion

What the day on 16 may 1992?

1992 = (1991)+(days between 1/1/1992 to 16/5/1992).
1600 = 0.
300 = 1.

91 = (22 leap)+(69 ordinary day).
= (22*2)+(69*1).
= 113 days.

= 16 weeks 1 day = 1 odd day.

Total 1991 yrs = 0+1+1 = 2 odd days.

jan feb mar april may
31 28 31 30 16 = 136 days.

= 19 weeks 3 days.

= 3 odd days.

Total till 16 may 1992 = 2+3 = 5.
5 = FRIDAY.
But in actual calendar it's SATURDAY. CAN I get the correct method to find it?

August 15th,2010 = (2000) +
(from 2001 to 2009) +
(from 1st January 2010 to 15th august 2010).

Odd Days in 2000 = 0.
Odd Days (from 2001 to 2009) = 2 Leap Year+7 Ordinary Year
= (2*2)+(7*1)
= 11%7 = 4 Odd Days.

Odd Days (from 1st January 2010 to 15th august 2010):

Jan = 31.
Feb = 28(not a leap year).
mar = 31.
Apr = 30.
May = 31.
Jun = 30.
Jul = 31.
Aug = 15.
===========
Tot = 227.
===========

Find Odd Days : 227%7 = 3(Odd Days).

Answer : Add all Odd Days = 0+4+3 = 7.

Notes for Odd Days : Number of days more than a complete week is
called as "Odd Days".

So, you have to divide 7 by 7.

Final Answer = 7%7 = 0 (Sunday)

friends, Let me introduce a technique which is used to find any day with any date from 1900 to 2999.

This is called doomsday technique;

doomsday means:

Last day of feb.

4th april(04.04)
6th june (06.06)
8th august(08.08)
10th oct(10.10)
12th dec(12.12)

To find doomsday of any year we should do,

anchor+(y/12)+remainder(y/12)+(remainder(y/12)/4).

For any period from 1900 to 1999 anchor = 3(wednesday).
For any period from 2000 to 2999 anchor = 2(tuesday) .
y means last 2 digits of the given year.

Now, our question here is to find the day on 15.08.2010
So,anchor=2, y=10.

2+(10/12)+rem(10/12)+(rem(10/12)/4).
2+0+10+2 =14.
14/7 = 0 so 0 odd days.
So dooms day is sunday.

For our question aug 8 is nearer. So, 08.08.2010 is surely sunday
add another 7 to 0 odd days. because 8+7=15. i.e 8th aug + 7 days = 15th aug.

0+7 odd days=7 odd days=7/7=0.

So the day is Sunday.

My dear how take 1600 years and 400 years And how leap year multiply by 2X2?

Hello everybody ,
You must know some codes first.

Years, Days, Century code(for every 400 years ).
Jan-0, sun-0, 0:99-6.
Feb-3, mon-1, 1:199-4.
Mar-3, tue-2, 2:299-2.
Apr-6, wed-3, 3:399-0.
may-1, thr-4,
Jun-4, fri-5,
Jul-6, sat-6,
Aug-2.
Sep-5.
Oct-0.
Nov-3.
Dec-5.

Now formula is ,

Day = (Date+month code+no.of years+no.of leap years + century code)/(7).

In the given question 15th Aug 2010.

Day = (15+2+10+2+6)/7 = 7/7 = 0. Which is 'Sunday'. :).

@Gpvsai : 15+2+10+2+6 = 35.

So, dividing 35 by 7 we get 5 which is friday.

I am not able to understand that how you calculate ordinary and leap years in 100 years, 97 years.

Is there any formula for that?

@Sunita.

97 year == Divide 97 by 4:
= Quotient is 24.
= So 24 is leap year and in 1 leap year has 2 odd days.
= Than (97-24= 73): 73 is ordinary year and 1 ordinary year has 1 odd day.
= 24*2 + 73*1= 121 days.
=121/7 = than reminder equal to 2.
= So 2 is odd days.

Year Code Month Code Day Code

1600-1699=6 Jan-0 Sun-0
1700-1799=4 Feb-3 Mon-1
1800-1899=2 Mar-3 Tue-2
1900-1999=0 Apr-6 Wed-3
2000-2099=6 May-1 Thu-4
2100-2199=4 Jun-4 Fri-5
July-6 Sat-6
Aug-2
Sept-5
Oct-0
Nov-3
Dec-5

Note: Day+Year+Leap Year+Year Code+Month Code

First we need to calculate leap year; it is calculated on 2010 and we need to take last two digits i.e;(10).

2)10(5
10
----
0 leave 0 and take only quotient i.e;5

Now come to formula
D+Y+L.Y+Y.C+M.C ==> 15+10+5+0+2 = 32.

2)32(16
2
------
12
12
------
0

The 0 shows day's code.
.'.2010 Aug 15th is Sunday.

Note: While calculating leap year, take last two digits from the year.
And considering year in the problem we need to take last two digits (i.e;10 in the problem).

Thank You & Regards,
Arjun.

Please explain how to take 9 years = 2 leap years + 7 ordinary years.