Problems with Published Dates

Running:
Windows 7 SP1
Calibre 2.53

After importing an eBook into Calibre I fix the metadata. Usually it is just one or two eBooks so I wasn't sure if the eBooks were at fault or some Calibre setting changing the published date when imported.

I just imported 10 new eBooks and everyone of them has the published date as Apr 2014. The year is correct but the month is wrong. This has been happening for awhile now. Whatever month I import the eBook is given for the published month. Year seems to be correct. It is just weird.

Is there some setting in Calibre I need to fix? Some setting on my computer? Is there a way for me to check the metadata in an eBook before adding it to Calibre?

Thanks for any help!