Conditional formating to highlight problems.
in Excel 2007 and if you have a cell (say C2) with the value of elapsed time (for example set = A2 which contains start time plus B2 which contains end time - or current time) - click in the cell (C2) then on the Home tab click on Styles >> Conditional formatting choose Highlight Cells Rules>>Greater Than... set your value in the dialog to your respective value and choose your highlight. This is a start - you can then add new rules.
to then apply this same conditional formatting to every cell in that column Ctrl-C to copy the cell you just formatted - then click on the column header to highlght the entire column - Right-click and choose Paste Special - then choose Formatting for what to paste.
It's slightly different in Excel 2003 so let us know what version you are using.