Adding value to last cell in table column

[GazNicki]

Hello.

I’m creating a spreadsheet to calculate working time, and need to ensure I’m using the correct reference period. I have a sheet that works, using a table, that requires I manually enter a number in the last cell of the last column.

The table expands daily when new figures are added manually, such as the date and times.

However, the very last cell in the last column is what I need to be a set number (119 in this instance). The cells in that column prior need to be the final cell -1.

Is there an IF statement that detects the final cell and can place the number 119 in it, and if it isn’t take the value of the cell below it and subtract 1?

Bearing in mind that the table expands from the bottom?

 

[GlennUK]

Use a formula (in row 2, as am assuming headers are in row 1), in the column which references an entire column of data (excluding header) to test if last row, like:
=IF((ROW()-1)=ROWS([Dept]),119,C3-1)