How to Solve Calendar Date Problems Quickly
There are 12 months listed on a calendar which makes a whole year. Each month either has 30 or 31 days in it. February is the only month made up of 28 or 29 days. There are seven days a week and a month has 4 weeks in it. One day consists of a total of 24 hours. Let us now learn about how to calculate dates.
How to Calculate Days: Basics
To calculate the number of days between two dates, we must first determine the number of days in each calendar month.
January, March, May, July, August, October, and December are the months that have thirty-one days.
April, June, September, and November are the months that have thirty days.
Months with 28 days - February (February in a leap year has 29 days)
The number of days between two dates can be calculated by the simple operation of addition and subtraction.
Calendar Of 2022
How to Calculate Calendar Days
Let's look at how to calculate the number of days between two dates using the solved example below.
Find the number of days between 10 January and 10 March.
Step one: Calculate the number of days in the month of January from the given date by subtracting it from the total days of the month. While subtraction we will omit a day so that needs to be added to the calculation.
Step two: Calculate the number of days in march till the given date. Here 1 should be subtracted as during calculation one extra would get added.
Step three: Add the number of days you got from step one, and step two and the number of days present in the month of February.
Number of days in January\[ = 31 - 10 + 1 = 22\]
Number of days in March\[ = 10 - 1 = 9\]
Number of days between 10 January and 10 March \[\begin{array}{l} = {\rm{ }}days{\rm{ }}in{\rm{ }}January{\rm{ }} + {\rm{ }}days{\rm{ }}in{\rm{ }}February{\rm{ }} + {\rm{ }}days{\rm{ }}in{\rm{ }}March\\ = 22 + 28 + 9\\ = 59\end{array}\]
How to Calculate Days a Fortnight Before or After?
This is another type of day calculation question in which a fortnight before or after is asked. You should know that a fortnight consists of 14 days. To calculate a fortnight before you need to subtract 14 from the given date and need to add 14 if asked for a fortnight after the given date.
Conclusion
The calendar date calculation is used to calculate the number of dates between two days of the same or different months. Through this, it makes it easy to know the number of days between the current date and the big event that might be coming up. We can also do the countdown based on these calculations.
Sample Questions
1. If today is Sunday, what was the day before yesterday?
a. Wednesday
b. Thursday
c. Friday
d. Saturday
Ans: Friday
Explanation: If today is Sunday then yesterday would have been Saturday and the day before yesterday would be Friday.
2. If today is Monday, what will be two days after today?
a. Wednesday
b. Thursday
c. Friday
d. Saturday
Ans: Thursday
Explanation: If we count two days after Monday we will get Thursday and between Tuesday and Wednesday are present.
3. If today is 29 April what was the date a fortnight before?
a. 12
b. 13
c. 14
d. 15
Ans: 15
Explanation: To find the date a fortnight before we need to subtract 14 from the mentioned date. So if we subtract 14 from 29 we will get 15. A fortnight before 29 April was 15 April.
FAQs on Calendar Date Calculation Made Easy
1. What is the fundamental concept for calculating the day of the week for a given date?
The fundamental concept is using a reference day and counting the total number of 'odd days' between the reference date and the target date. An odd day is any day remaining after grouping the total days into full weeks (dividing by 7). By knowing the starting day and adding the odd days, you can determine the day of the week for any date in the past or future.
2. How do you determine if a year is a leap year?
To determine if a year is a leap year, you can follow two simple rules as per the Gregorian calendar system.
- A year is a leap year if it is divisible by 4, except for century years.
- A century year (like 1800, 1900, 2000) is a leap year only if it is divisible by 400.
3. What are 'odd days' and how do they simplify calendar calculations?
In calendar calculations, 'odd days' are the number of days remaining after dividing the total number of days in a period by 7. For instance, a normal year has 365 days, which is 52 weeks and 1 odd day (365 ÷ 7 leaves a remainder of 1). A leap year has 2 odd days. This concept simplifies calculations because the day of the week only depends on this remainder. Instead of tracking hundreds of days, you only need to track these few odd days to find the final day of the week.
4. Why are leap years necessary in our calendar?
Leap years are necessary to keep our calendar in alignment with the Earth's revolutions around the Sun. The Earth takes approximately 365.2425 days to complete one orbit, not exactly 365 days. If we didn't add an extra day (February 29th) nearly every four years, our calendar would drift out of sync with the seasons. Over a century, the calendar would be off by about 24 days, causing seasons like summer to start in what our calendar would call a different month.
5. How many days does each month have in a standard year?
The number of days in each month is fixed and essential to remember for calendar calculations. Here is a breakdown:
- 31 days: January, March, May, July, August, October, December
- 30 days: April, June, September, November
- 28 days: February (in a normal year)
- 29 days: February (in a leap year)
6. What is a simple way to find the number of weeks in a year or a month?
To find the number of weeks, you divide the total number of days by 7.
- In a year: A normal year has 365 days, which equals 52 weeks and 1 extra day (365/7 = 52 with a remainder of 1). A leap year has 366 days, which is 52 weeks and 2 extra days.
- In a month: Since months have 28, 30, or 31 days, they all contain at least 4 full weeks (4 x 7 = 28 days), plus some extra days. For example, a 31-day month has 4 weeks and 3 extra days.
7. How does using a century code make calendar date calculations easier?
A century code is a shortcut used in algorithms to find the day of any date. It is a number that represents the total odd days for the completed centuries (e.g., for the 1900s, you'd use the code for the period up to 1899). Since the pattern of odd days repeats every 400 years, you can memorise a simple code (like 0, 5, 3, 1 or 6, 4, 2, 0 depending on the method) for a 400-year cycle. This allows you to quickly account for hundreds of years in your calculation without adding them up individually, making the process much faster.
