Important Points for Calendar topic of Reasoning Section for Exams

Reasoning section is the most scoring section for the aspirants and it covers 50 marks in every exam of Government job. It can be easy for the aspirants to score 45+ in this section, if prepared and practiced well.
Calendar topic also covers 1-2 mark question in Reasoning section. So, we are going to discuss basic concepts and points before we start calculation to find day of date.

How Odd days are calculated:

- You know there are 7 days in a week. And, there are 365 days in General Year and 366 days in Leap Year.
Hence, Odd days can be defined the remainder of a number when divided by 7. 
Now, to find ODD days:

• 365/7 = 1 odd days. 
• And, 366/7 = 2 odd days.

Find ODD days in a month:

•  Let's take an example of January (31 days).
• 31/7 = 3 odd days.
• Similarly, Odd days for every month can be calculated.

Important Points need to remember: 

- Earth completes the revolution in 365 days, 5hour, 48 minutes and 47 seconds.

- In 365 days, 52 weeks and 1 odd days.
- In 366 days, 52 weeks and 2 odd days.

- In 100 years, there are 5 odd days.
- In 200 years, there are 3 odd days.
- In 300 years, there are 1 odd days.
- In 400 years, there are 0 odd days.  .

Odd days in General Year (365 days):

• Jan- 3 odd days; Feb- 0 odd day; Mar- 3 odd days. Now, take take together, sum will 6 odd days. So, from 1-3 months, there are 6 odd days.
• Similarly, from Jan to June (1-6 months), there are 6 odd days.
• Similarly, from Jan to September (1-9 months), there are 0 odd days.
• Similarly, from Jan to Dec (1-12), there are 1 odd days.

- Short trick has been evaluated from this. When you have to find odd from first six months you know that there are 6 odd days. Hence, reduced the calculation. And, it can remembered as "6601"

Odd days in Leap Year (366 days):

• Jan- 3 odd days; Feb- 1 odd day; Mar- 3 odd days. Now, take take together, sum will 7 odd days. So, from 1-3 months, there are 0 odd days.
• Similarly, from Jan to June (1-6 months), there are 0 odd days..
• Similarly, from Jan to September (1-9 months), there are 1 odd days.
• Similarly, from Jan to Dec (1-12), there are 2 odd days.

- Short trick has been evaluated from this. When you have to find odd from first six months you know that there are 6 odd days. Hence, reduced the calculation. And, it can remembered as "0012"

When the Calendar repeat itself:
- In 1900 to 2100 years, the calendar repeats itself in the same format. It means

1. If the present year is leap year, the same date and day calendar format will come after 28 years. 
2. After leap year, this year will be repeated in 6 years.
3. Next year, it will be repeated in 11 years.

Ques-1: Ram is born on 18, March, 2008. When the same day on this date will again be repeated.
Ans: 2008 is leap year. Hence, add 28 years in it. The same calendar will come on 2036.