Input

J, integer
K, integer
I, 4-digit integer

Interface

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DayOfWeek(J, K, I) 
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Process

BEGIN 
  A <- (14 - J) div 12
  Y <- I - A
  M <- J + 12 * A - 2
  N <- (K + Y + Y div 4 - Y div 100 + Y div 400 + (31 * M) div 12) mod 7;
  DayOfWeek <- N 
END 

Output

DayOfWeek, integer 

Notes

Determines the day of the week on which a given date falls. J is month, K is day of month and I is 4-digit year.
The algorithm is based on information at www.smart.net/~mmontes/ushols.html#ALG [site no longer exists; jdr 1/2/2021].
DayOfWeek is a 1-digit integer corresponding to a day of the week where:
0=Sunday, 1=Monday, 2=Tuesday, 3=Wednesday, 4=Thursday, 5=Friday, 6=Saturday

Examples

Input                   Output 
J       K      I        DayOfWeek 
7       15     1996     1 
10      9      1996     3 
10      31     1996     4 

Notation

<- means is replaced by 
J div K yields the quotient after long division of J by K 
J mod K yields the remainder after long division of J by K