### Chapter: Calendar

Important formulae and tricks and shortcuts of Calendar:

We are providing you Important Concepts and Tricks on Calendar which are usually asked in almost all competitive exams like IBPS, Govt. Exams and CAT and in quantitative aptitude of MNCs. Use these below given tricks to solve questions within minimum time. These tricks will be very helpful for your upcoming Competitive Exam.

In order to solve these type of problems you must know some codes.
• Year Code
• Month Code
• Day Code
Year Code:-
 1600-1699 6 1700-1799 4 1800-1899 2 1900-1999 0 2000-2099 6
Month Code:-
 Jan Feb Mar April May June July Aug Sep Oct Nov Dec 0 3 3 6 1 4 6 2 5 0 3 5
Day Code:-
 Sunday Monday Tuesday Wednesday Thursday Friday Saturday 0 1 2 3 4 5 6
Steps to solve:-
Step 1: Add the day digit to last two digit of the year.
Step 2: Divide the last two digits of the year by four.
Step 3: Add the Quotient value in step 3 to result obtain in step 1.
Step 4: Add Month Code and year codes to the result obtain in step3.
Step 5: Divide the result of step4 by seven.
Step 6: Obtain the remainder and match with the day code.

Other Formulas:

Odd Days:

We are supposed to find the day of the week on a given date.

For this, we use the concept of 'odd days'.

In a given period, the number of days more than the complete weeks are called odd days.

Leap Year:

(i). Every year divisible by 4 is a leap year, if it is not a century.

(ii). Every 4th century is a leap year and no other century is a leap year.

Note: A leap year has 366 days.

Examples:

Each of the years 1948, 2004, 1676 etc. is a leap year.

Each of the years 400, 800, 1200, 1600, 2000 etc. is a leap year.

None of the years 2001, 2002, 2003, 2005, 1800, 2100 is a leap year.

Ordinary Year:

The year which is not a leap year is called anordinary years. An ordinary year has 365 days.

Counting of Odd Days:

1.1 ordinary year = 365 days = (52 weeks + 1 day.)

∴∴ 1 ordinary year has 1 odd day.

2.1 leap year = 366 days = (52 weeks + 2 days)

∴∴ 1 leap year has 2 odd days.

3.100 years = 76 ordinary years + 24 leap years

= (76 x 1 + 24 x 2) odd days = 124 odd days.

= (17 weeks + days) 5 odd days.

Number of odd days in 100 years = 5.

Number of odd days in 200 years = (5 x 2) 3 odd days.

Number of odd days in 300 years = (5 x 3) 1 odd day.

Number of odd days in 400 years = (5 x 4 + 1) 0 odd day.

Similarly, each one of 800 years, 1200 years, 1600 years, 2000 years etc. has 0 odd days.

For solved problems on above formulas please visit below sections: