ok, as it turns out i've somewhat figured out how to work formulas, which is a bonus. now my main problems are back to formatting. for the lunch, i need it in H:MM format, and can't seem to get it formatted properly. if i open up the spreadsheet and reformat the decimal values or datetime values that are there, i get the correct result, so i know the formula is doing its job, it's just my formatting that is incorrect. i also need decimal values...

thanks for the help, that did the trick. now i'm stuck on the formulas part and can't seem to find a good tutorial for writing the formulas i want. my spreadsheet will look something like this:

i need to subtract the first "out"...

i am using a php script to generate excel xml. everything works fine as long as the datatype is "String", but nothing quite works right when i switch the datatype to "DateTime". the best i can get is to show a decimal value in the fields i have set to "DateTime", not the standard user-friendly excel display (eg "10:39:00") . i also am trying to write simple formulas to subtract time but have not had any success....