First, your first post of this question is has a time of 4:05 AM, the second
4:10 AM, the third 6:11 AM, and this one is 9:33 AM. I am located on the East
Coast and so I was still in bed when your first three messages posted.

Second, the list does not allow attachments. There is a files area where you can
upload files and referfence them there.

In response to your question:

What type of column is 'Report Date'? Is it a DateTime Column or is it
calcullated?
Are there any items in the library that have a 'Report Date' = 4/6/208?

Sorry for inconvenience
I was curious about after posting 2 times my question it is not available in
this forum that's why
I posted it again, well thanks for reply,

Yes ReportDate is DateTime colums and there are other items available in
doc lib for 4/6/2008. why it contains 4/7/2008 date groping items?

My first guess would be the time zone settings. As an example our IIS server
logs cutoff at midnight; but that is midnight ZULU, Greewhich Mean Time.
Consequently, local times cross the logs;e.g., the first entry in the logfile
for today 4/09/2008 starts with 2008-04-08 20:00:18 W3SVC1 ... becuase we are 4
hours behind ZULU time.