First I strongly advise you to rename your [Date/Time] field if possible...
-alphanumeric:
Access 2007 reserved words and symbols AllenBrowne- Problem names and reserved words in Access
If this is from a server, then your DBA has done you no favors in using reserved words and symbols and IMHO should be sent back to remedial database design.
If the query is displaying the correct information, then (not to state the obvious
:-D
) something in the chart formatting may be off.
Open in design mode.
Right click the axis in the chart
Select formt axis from the pop-up menu
Set the scale and the number formating
yea.