Please Help me solve this SQL

Hi All,
Excuse me for asking very stupid SQL question. Say I have a transaction table called trans_test having one of columns as mod_date ( this is defined as datetime type). I need to list all records inserted into this table during past half hour.

Oracle in my home computer is hosed up and therefore not able to test the SQL myself. So guys please try to help me.

Thanks

select sysdate - 1/48 from dual;

Thanks Pando. But this will return me the time that was half hour ago. I need this time to compare with column values of my table.

something like :

select * from trans_table where mod_date > sysdate - 1/48;

where mod_date is of type Datetime.

Do I need to use to_date function in SQL? or any other function?

I am not quite sure of syntax. So just wanted to make whether my syntax is right. I dont have sqlplus working in my machine and I need to help a friend who has asked me for this.

Thanks for the help.

that should work, date - date still gives you date datatype

Thanks Again Pando. Just needed a nod.