Try:
<font face=Courier New><SPAN style="color:#00007F">Sub</SPAN> exa7()<br><SPAN style="color:#00007F">Dim</SPAN> dbl <SPAN style="color:#00007F">As</SPAN> <SPAN style="color:#00007F">Double</SPAN><br><SPAN style="color:#00007F">Dim</SPAN> dtm <SPAN style="color:#00007F">As</SPAN> <SPAN style="color:#00007F">Date</SPAN><br><SPAN style="color:#00007F">Dim</SPAN> i <SPAN style="color:#00007F">As</SPAN> <SPAN style="color:#00007F">Long</SPAN><br> <br> dbl = 1 / 86400 * 600 * 35<br> <br> <SPAN style="color:#00007F">Do</SPAN> <SPAN style="color:#00007F">While</SPAN> dbl < 0.99<br> i = i + 1<br> dbl = dbl + 1 / 86400 * 600<br> dtm = <SPAN style="color:#00007F">CDate</SPAN>(dbl)<br> Cells(i, 1).Value = Format(dbl, "hh:mm") & "-" & Format(dbl + 1 / 86400 * 600, "hh:mm")<br> <SPAN style="color:#00007F">Loop</SPAN><br><SPAN style="color:#00007F">End</SPAN> <SPAN style="color:#00007F">Sub</SPAN></FONT>