kaps,
I would suggest loading the file in Excel using ActiveX and then changing the cell format for the multiple times. LabVIEW writes out the information you want, but Excel defaults to a different cell format.
A good example if the "Export Waveforms to a Spreadsheet File" shipping example for LabVIEW. Make a small modification to the block diagram to have LabVIEW write multiple times and then open the file in a text editor. You will see the full date and time written to the file.
Randy Hoskin
Applications Engineer
National Instrumetns
http://www.ni.com/ask