You may want to clone your portfolio first. To do so please click here.
Then, from the "Portfolios" section, click on the portfolio you want to set date as of today.
Now click on "Edit", at the top.
Change the date to today´s date then hit "Save".
By doing so, you will be able to reflect the changes in market conditions from the portfolio date to today. You will also capture the "roll" from securities with set maturities.