Let us understand this technique through an example:
Find out the day of 3rd April 2014
Solution:
3rd April 2013 has 13 complete years ( we will not take 14th year as it is not complete)
In 13 complete years, there are 3 leap years and 10 ordinary years
To find out numbers of leap years follow these steps:
Number of odd days in a leap year = 2
Number of odd days in 3 leap years = 2x3=6 odd days
Number of odd days in an ordinary year =1
Number of odd days in 10 ordinary years = 1x10=10 odd days = 3 odd days
Please note If the total number of odd days are 7 or more than 7 , divide the total by 7 to find out exact number of days . Here in this case the total is 10. So when we divide it by 7 , the reminder is 3 which is the exact number of odd days .
Now count the number of odd days from January 2014 to 3rd April 2014
Odd days in January: 3 ( 31/7 gives remainder 3)
Odd days in February : 0 ( 28/7 gives remainder 0)
Odd days in March : 3 ( 31/7 gives remainder 3)
Odd days in April: 3(since we have to calculate till 3rd of April)
So the total odd days = 3+0+3+3=9 means 2 odd days( 10/7 gives remainder 2)
Now add all odd days
6 odd days+3 odd days + 2 odd days = 11 odd days means 4 odd days
Now remember this table:
4th odd day in the table is Thursday. So 3rd April 2014 was Thursday.
3 leap years means 3 x 2 = 6 odd days means
12 ordinary years means 12 odd days i.e. 5 odd days (12/7 remainder 5)
Jan 2016 has 3 odd days ( 31/7 remainder 3)
Feb 2016 has 1 odd day ( 29/7 remainder 1)
March 2016 has 3 odd days (31/7 remainder 3)
April 2016 has 2 odd days (30/7 remainder 2)
May 2016 has 3 odd days (31/7 remainder 3)
June has 15 odd days ( till 15th June )
Total odd days = 3+1+3+2+3+15=27 odd days i.e. 6 odd days (27/7 remainder 6)
Add all odd day that you found
6 odd days+5 odd days+6 odd days = 17
17/7 remainder is 3
Look at the table
So 15th June 2016 will be Wednesday.
90 we will take 89 complete year ( because 90 is not a complete year)
Total odd days = 2 + 5 +4 =11 means 4 odd days (11/7 remainder 4)
Look at the table
4 means Thursday
4th January 1990 was Thursday .
Find out the day of 3rd April 2014
Solution:
3rd April 2013 has 13 complete years ( we will not take 14th year as it is not complete)
In 13 complete years, there are 3 leap years and 10 ordinary years
To find out numbers of leap years follow these steps:
Divide 13 by 4
The remaining years (13-3=10) are ordinary years so
Number of odd days in 3 leap years = 2x3=6 odd days
Number of odd days in an ordinary year =1
Number of odd days in 10 ordinary years = 1x10=10 odd days = 3 odd days
Please note If the total number of odd days are 7 or more than 7 , divide the total by 7 to find out exact number of days . Here in this case the total is 10. So when we divide it by 7 , the reminder is 3 which is the exact number of odd days .
Odd days in January: 3 ( 31/7 gives remainder 3)
Odd days in February : 0 ( 28/7 gives remainder 0)
Odd days in March : 3 ( 31/7 gives remainder 3)
Odd days in April: 3(since we have to calculate till 3rd of April)
So the total odd days = 3+0+3+3=9 means 2 odd days( 10/7 gives remainder 2)
Now add all odd days
6 odd days+3 odd days + 2 odd days = 11 odd days means 4 odd days
Now remember this table:
| 0 | Sunday |
| 1 | Monday |
| 2 | Tuesday |
| 3 | Wednesday |
| 4 | Thursday |
| 5 | Friday |
| 6 | Saturday |
4th odd day in the table is Thursday. So 3rd April 2014 was Thursday.
- · Find out the day on 15 June 2016.
12 ordinary years means 12 odd days i.e. 5 odd days (12/7 remainder 5)
Jan 2016 has 3 odd days ( 31/7 remainder 3)
Feb 2016 has 1 odd day ( 29/7 remainder 1)
March 2016 has 3 odd days (31/7 remainder 3)
April 2016 has 2 odd days (30/7 remainder 2)
May 2016 has 3 odd days (31/7 remainder 3)
June has 15 odd days ( till 15th June )
Total odd days = 3+1+3+2+3+15=27 odd days i.e. 6 odd days (27/7 remainder 6)
Add all odd day that you found
6 odd days+5 odd days+6 odd days = 17
17/7 remainder is 3
Look at the table
0 | Sunday |
| 1 | Monday |
| 2 | Tuesday |
| 3 | Wednesday |
| 4 | Thursday |
| 5 | Friday |
| 6 | Saturday |
- Find the day on 4th January 1990
90 we will take 89 complete year ( because 90 is not a complete year)
Total odd days = 2 + 5 +4 =11 means 4 odd days (11/7 remainder 4)
Look at the table
| 0 | Sunday |
| 1 | Monday |
| 2 | Tuesday |
| 3 | Wednesday |
| 4 | Thursday |
| 5 | Friday |
| 6 | Saturday |
4th January 1990 was Thursday .
