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.
Use the DATEDIF function to calculate the number of days, months, or years between two dates. DAYS function. Use this function to return the number of days between two dates. FIND, FINDB functions. FIND and FINDB locate one text string within a second text string.