claus i cant start in a1 and b1 due to other information being in there, i will try your code a little later to edit the cells. and hokie_16 everytime i try i get the false command when trying =time(h,m,s). i forgot to tell you guys i use a list on another sheet, so i can do my drop down box to pick the times.

the code =IF(C1=TIME(12,0,0),TIME(1,0,0),TIME(0,30,0)) seems to be working fine, except boxes that are empty are displaying 00:30:00 instead of nothing.

also because of changing the formats to times instead of custom, before we used to work out the holiday as - holiday days allocated times 7.18 (1 day in a 36.5 hour week. but now i cant do that as im trying to get the sheet to do fully in time, for example old way was 31 days *7.18 = 222.58 hours worth of holiday. ive tried doing 7.18 (time) * 31 but i get back 10:18:00

stumped!

and thanks guys so far for your help
edit: hmmm think ive sorta found out whats going on in the total shift hours box but not sure how to fix it. basically because im using time, it will never go past 23:59:00. so if i did time addition for example 11:00:00 + 11:00:00 + 11:00:00 - instead of saying 33:00:00 to minus off my total holiday hours remaining it will say 09:00:00

added a picture