SESSION start time - sysdate

Hi - Please help on DML INSERT statement for SYSDATE built-in function.

I been using INSERT statment to  insert around 30 million rows in a table with 10 columns.In that table there is DATE column also.I am using SYSDATE Built-In-Function in INSERT VALUES for DATE column.The INSERT statement is running nearly 5 hours.

The DATE column needs to have to the SESSION start time ONLY for all 30 million rows.In other words 30 million rows should show one time stamp that is SESSION start time including minutes and seconds.

How can achive this?Is there any Built-In-function?Please advice.

Thanks in advnace.