[comp.lang.asm370] Day-of-week calculation

FISHER@RPIECS.BITNET ("John S. Fisher") (01/05/90)

More REXX code.  The DAYS procedure, below, computes number of days since
02/28/1900 for an mm/dd/yy date.  Use the remainder of that number divided
by 7 to get day of week.

/*********************************************************************/
/* DAYS    Compute days since 02/28/00.                              */
/*********************************************************************/
DAYS: Procedure;
 arg mm'/'dd'/'yy;
 mm = mm - 3;
 if mm < 0 then do;
    yy = yy - 1;
    mm = mm + 12;
 end;
 return( trunc((5+306*mm)/10) + dd + 365*yy + trunc(yy/4) );



/JSFisher