ok, iM trying to figure out a formula that calculates time..
Im working in construction domain and there is what i wanna do on my sheet..

i have cell that eqals the hours work during the day.. so .. C4 is the time
of beginning, C5 the time of ending, D1 is the time of dinner that i have to
take off every day. .. so my formula is =C5-$D$1-C4 till then it is ok but
the thing is if the person did not work at one point one day, the total stays
0.5 so what should i put in my formula that will equal "0" that day?.. been
searching for a while and now i'm out of ideas lolll...
Can anyone help me please? and thank you..