Complex date comparism and extraction in Excel

Hi,

I have a big spreadsheet consist of a date field with the following format:

Fri May 29 01:16:56 GMT+05:30 2009
Mon May 25 22:20:17 GMT+05:30 2009
Thu May 28 14:30:28 GMT+05:30 2009
.
.
.

I want to compare row by row on this field after being sorted. If date (ignore the time) is same or next day, return a value (Y). If date is not equal or not next day, return a different value (N).

Tried but could not get the formular working. Any expert advise appreciated.

Thanks