svg - How to animate text in SVG (possibly without using javascript)

Question

I doing SVG animation of some physical process using svg (basically I want whole animation as a single svg file).

Example can be seen here: https://s3.amazonaws.com/public-bucket-vzi0CDPFDE4ywJfvfylfpnDW/dwg.svg .

Now I'd like to add label stating: "Time: 1.23ns" displaying current time. I couldnt find any obvioius way to replace contents of text object, insert format current time inside text element.

It would also be great if this animation wasn't using javascript, just SVG animation.