SQL & PL/SQL :: Pivot Table Using UNIX Timestamp

I am trying to produce results in pivot format. I want to know how many entries per day per month. In other words how many entries on a Monday for each month, how many on a Tuesday for each month and so on.

The main problem I have is that the date column in the database uses UNIX time stamp. I have managed to get the results I want for a particular month. This code selects the entries for last month.

select
max(decode(pdayno, 1, cnt, null)) Sunday,
max(decode(pdayno, 2, cnt, null)) Monday,
max(decode(pdayno, 3, cnt, null)) Tuesday,
max(decode(pdayno, 4, cnt, null)) Wednesday,
[code].......

This code produces the result:

What I need is for another column at the start of the results to give the month so I end up with 12 rows, 1 for each month.

I did try to group by PENTERED(which is the unix time stamp column)
select pentered,
max(decode(pdayno, 1, cnt, null)) Sunday,
max(decode(pdayno, 2, cnt, null)) Monday,
max(decode(pdayno, 3, cnt, null)) Tuesday,
max(decode(pdayno, 4, cnt, null)) Wednesday,
[code]......

This gave me thousands of rows as each UNIX time stamp is unique. Is there a way of grouping on UNIX time stamp.