I have a huge amount of data where the Date columns contain dates in the format 3/3/2010 11:00:00 AM. But it is not possible to remove the time section,11:00:00 AM, using Replace or Format as Date. Is there any other way to
get rid of the time section from the date.
If your data is really a date with time in Excel time format it should be possible to just use a Date format to only show the date part.
You can find out if the data in cell A1 is in time format by testing with =ISNUMBER(A1)
If the result is TRUE, then a simple format should help.
But as you say you have tested that I assume that the result of this test is FALSE.
That means that the data is in text format (and you can't use it for arithmetics).
If that is the case you can filter out the date part of the text with this formula:
=LEFT(A1,FIND(" ",A1)-1)
Hope this helps / Lars-Åke