I don't think there's a dedicated function to do that. However, I think there's a way to do this:
1) Create a custom date field on the object where you're running Slide Publisher (Project?).
2) Update the Slide Publisher custom action to update the field created in step 1 to contain today's date using the OrganizationNow() function.
3) Use the field created in step 1 in your slide as you would use any other field.
I hope this helps.