Reading date values from excel cell using POI HSSF API

You could take a look at:

HSSFDateUtil.isCellDateFormatted()

See the POI Horrible Spreadsheet Format API for more details on HSSFDateUtil:

http://poi.apache.org/apidocs/org/apache/poi/hssf/usermodel/HSSFDateUtil.html

That also provides some helper methods for returning Excel getExcelDate() and Java dates getJavaDate(). You need to be somewhat wary of different date formats though…