I am creating a time sheet on Excel. I have a colum for time in, time
out, and total hours worked. In the total hours worked column I had to
use the formula: =((C8+12)-B8)-0.5

The -.05 refers to the half hour lunch that is not counted as hours
worked.

What kind of formula do I need in case someone is either sick or there
is a vacation day? When no number (or 0) is in the first two cells, my
total hours worked equals 11.5!

What can I do so that

(a) the total hours worked colum always equals zero if no numbers are
input

(b) lock the formulas so when I send this out, no one can change or
mess it up

I appreciate any help!

Carla