Aptitude calendar ppt

1. CALENDAR
Presented by
G.Rajeswari
AP/ Civil

2. QUICK VIEWS
• Ordinary Year
• Leap Year
• Odd Days
• Counting of odd days
• Day of the week with respect to the number of
odd days

3. EXPECTED QUESTIONS
• We are Supposed to find the day of the week
on the given date
• For this we use the concept of “ODD DAYS”

4. LEAP YEAR
• Every year divisible by 4 – LEAP YEAR
• It means last two digits of the year is multiples
of 4 then the year is said to be leap year
For Example
 2012 -------> 12/4 = 3
 1948 -------> 48/4 = 12
 2016 ------->16/4 = 4
 2020 ------->20/4 = 5
 1676 ------->76/4 = 19
 1824 ------->24/4 = 6

5. LEAP YEAR
• Every Century year divisible by 400 – LEAP
YEAR
• It means multiples of 400 is a leap year
For Example
 2000 -------> 2000/400 = 5
 1600 -------> 1600/400 = 4
 400 -------> 400/400 = 1
 1200 -------> 1200/400 = 3
 800 ------->800/400 = 2
 2400 ------->2400/400 = 6

6. Exception To be Noted
 A year 700 is completely divisible by 4, but it is
not considered as a leap year.
 For a century year, the logic follows that it
should always be divisible by 400 not by 4.
 Even though the year 700 is divisible by 4 but
not by 400. Hence, the year 700 cannot be
considered as a leap year.

7. ORDINARY YEAR
• Every year not divisible by 4 – ORDINARY
YEAR
• It means all the years except leap year is an
Ordinary year
For Example
 2019 -------> 19 not divisible by 4
 1927 -------> 27 not divisible by 4
 2015 ------->15 not divisible by 4
 2021 ------->21 not divisible by 4
 1675 ------->75 not divisible by 4
 1831 ------->31 not divisible by 4

8. NOTE
• An ordinary year has 365 days
• Split days as weeks – 365/7 = 52 + 1
 52 Weeks + 1 extra day
• A Leap year has 366 days
• Split days as weeks – 366/7 = 52 + 2
 52 Weeks + 2 extra days

9. ODD DAY
• In the given period the number of days more
than the complete weeks are called
“odd days”
• In a year an extra day is referred as odd day
A Leap year has 2 odd days
An Ordinary year has 1 odd day

10. DAY TO REMEMBER
No.of odd daysin a year Day
0 Sunday
1 Monday
2 Tuesday
3 Wednesday
4 Thursday
5 Friday
6 Saturday

11. NO. OF ODD DAYS FOR 1ST 400 YEARS

12. NO. OF ODD DAYS IN A MONTH

13. PROBLEMS ON NON-LEAP YEAR
Q.1 Which day of the week was 12th February 1941 ?
 1941 = 1600 + 300 + 40 yr + Jan + 12 Feb
= 0 + 1 + ( 10 leap yr + 30 ord yr) + 3 + 12
= 0 + 1 + ( 10 x 2 + 30 x 1 ) + 3 + 12
= 66 odd days
 Split into weeks = 66/7 = 9 weeks + 3 odd days
The 3rd odd day is WEDNESDAY

15. PROBLEMS ON NON-LEAP YEAR
Q.2 Which day of the week was 18th April 1963?
 1963 = 1600 + 300 + 62 yr +( Jan to March) + 18 Apr
= 0 + 1 + ( 15 leap yr + 47 ord yr) + (3 + 0 + 3) + 18
= 0 + 1 + ( 15 x 2 + 47 x 1 ) + 6 + 18
= 102 odd days
 Split into weeks = 102 / 7 = 14 weeks + 4 odd days
The 4th odd day is THURSDAY

17. PROBLEMS ON NON-LEAP YEAR
Q.3 Which day of the week was 2nd May 1921?
 1921 = 1600 + 300 + 20 yr +( Jan to April) + 2 may
= 0 + 1 + ( 5 leap yr + 15 ord yr) + (3 + 0 + 3 + 2) + 2
= 0 + 1 + ( 5 x 2 + 15 x 1 ) + 8 + 2
= 36 odd days
 Split into weeks = 36 / 7 = 5 weeks + 1 odd day
The 1st odd day is MONDAY

19. PROBLEMS ON NON-LEAP YEAR
Q.4 Which day of the week was 2nd December 1818?
 1818 = 1600 + 200 + 17 yr + ( Jan to Nov) + 2 Dec
= 0 + 3 + ( 4 leap yr + 13 ord yr) + (26) + 2
= 0 + 3 + ( 4 x 2 + 13 x 1 ) + 6 + 18
= 52 odd days
 Split into weeks = 52 / 7 = 7 weeks + 3 odd days
The 3rd odd day is WEDNESDAY

20. QUESTIONS
• Which day of the week was
i. 4th June 1931
ii. 7 November 1945
iii. 1st April 1841
iv. 5th February 1770

21. ANSWER
• Which day of the week was
i. 4th June 1931 - THURSDAY
ii. 7 November 1945 - WEDNESDAY
iii. 1st April 1841 - THURSDAY
iv. 5th February 1770 - MONDAY

22. THANK YOU