What would be the optimum surrounding light for editing ?
Should i have 2 monitor profiles
One for day
One for night lights on ?
Mostly, you want the ambient light to be low enough that it has little effect on your adaptation to white. A secondary reason is that it's good to minimize glare from ambient reflections. I use 100 cd/m^2 for the monitor and about 60 lux ambient impacting the screen. However, the room ambient is about 100 lux at 3000K. That probably isn't optimal but I don't find it affects things too much as the monitor gray surround is brighter.
However, the brightness of surround is important. One perceives smaller changes in tone which are near the surround as larger than the same changes which are removed from the surround. This perceptual difference can change how you adjust a photo.
I have a 31" monitor and so I typically use a middle gray background and, if an image is to be displayed with a white border I'll put an appropriately sized background white layer to simulate how it will appear. OTOH, if a print is to be displayed with a flood against a darker wall w/o a white border I'll work with a dark gray background and no white layer.
I can't comment about day/night. My room has a curtained, small, North facing window so there is little difference.
