Your kneecap (patella) sits over the front of your knee joint. As you bend or straighten your knee, the underside of the patella glides over the bones that make up the knee. Strong tendons help attach the kneecap to the bones and muscles that surround the knee.
NETWORKDAYS.INTL(D3,E3,0000000) calculates whole days between the two dates (no weekends, no holidays). NETWORKDAYS(D3,E3,0000000,$A$16:$A$24) calculates whole working days days between the two dates (Sat/Sun weekends, holidays as per your list in $A$16:$A$24). Difference in non-working days between the two dates.
In order to calculate the number of pay periods in a year, you divide the number of weeks in a year (52) by the frequency of payroll payments. Fifty-two divided by two equals 26. This figure may be adjusted to compute for unpaid vacation time. For a worker who receives two weeks of unpaid vacation, the equation changes.