MJPG-streamer adding date and time

Hi,
I got finally OpenWRT working in R8000 and added USB Webcam to it, installed MJPG-streamer, connected to NAS drive where files are nicely stored and handled.

As tweaking in more, I would like to add timestamd directly to stream.

Does someone know or have an idea how to add already in MJPG-streamer time and date as "burned in picture" ?

Best Regars,
Pasi