Day from any date without code

Find Day from any given Date

 Hello dear students,
    If you are preparing for any compitative examination like SSC, Bank, Railway, TET, TGT, PGT etc or any other compitative exam, then this post will be very helpful to you.
 After learning this trick you can find Day of any date without any code.
  Before starting, we should know some basic concepts:-

Day:- A time of  24 hours is known as a day.
Week:- This is the time of 7 days.  or a group of 7 days make a week.

1. Sunday
2. Monday
3. Tuesday
4. Wednesday
5. Thursday
6. Friday
7. Saturday
Month:- A month contains 30 or 31 days but February has 28 or 29 days.
  If we divide a month into week then we can get some week and extra days.
 e.g.- January has 31 days. If we convert it into week then we can easily calculate  31=7×4+3
As you can see there is 4 weeks and 3 extra days in the month of January 
Sr.   Month         Days        Extra days 
 1.     January.          31.            3
2.     February.       28/29.       0/1
3.     March.            31.            3
4.     April.               30.            2
5.     May.                 31.           3
6.     June.                 30.           2
7.     July.                  31.           3
8.     August.            31.           3
9.     September.      30.           2
10.   October.           31.          3
11.    November.      30.          2
12.   December.       31.          3
Year:- A year has 12 months as above.
        A normal year has 365 days but a leap year has 366 days. In a leap year February has 29 days and it comes after every four year. 
   *Which year divides by 4 that will be leap year.
e.g. 2004 is a leap year because it is completely divided by 4.
* Normal year has 52 weeks and 1 extra day.
* Leap year has 52 weeks and 2 extra days.
Century leap year:- Which year divides by 100 that will be century leap year.
e.g. 2000 is a century leap year.

*Trick*

Let's take an example 15-08-2020
1. Subtract 1 from the given year
      2020-1=2019
2. Now take 2019 and try to divide it by 100, 200, 300 or 400 and keep extra days code for these- 
  For.  100-        5 extra days
           200-        3 extra days
           300-        1 extra days
           400-        0 extra days
      e.g.   2019=400×5+19
3. Now divide 19 by 4 then we can get as
         2019=400×5+4×4+3
Now write extra day at the place of 400 and 4 as
       2019=0×5+2×4   ( leave the remainder 3)
                =8 extra days in leap years
4. There is 4 leap years in 19 years.
   Now subtract 4 from 19
 e.g.     19-4=15 extra days in normal years
  Extra days upto 2019= extra days in leap year + extra days in normal year
                  = 8+15
                  = 23 extra days
5. Sum extra days of every month of 2020 upto August 15
     Extra days of 2020= January+February+March+April+May+June+July+15 August
           = 3+1+3+2+3+2+3+15
           = 32 extra days in 2020
6. Total extra days= extra days upto 2019 + extra days of  2020
        = 23+32
        = 55 extra days
7. Now divide Total extra days by 7 and see the remainder.
         55=7×7+6
  The remainder is 6
8. Now obtain day by remainder-
 Remainder.             Day
     0                            Sunday
     1                            Monday
    2                             Tuesday
    3                             Wednesday
    4                             Thursday
   5                              Friday
   6                             Saturday
9. We have found remainder 6
    So, on 15 August 2020 will be. Saturday