[kqr]

Not only between displays, but also between lighting conditions in the environment where the display is used. In principle, you should recalibrate every time you switch bulbs – even more important any time the monitor moves to a different room!

[07d046]

My understanding is that calibrating the monitor only takes the light emitted from the monitor into account, so the environment doesn't matter for calibration. That said, the way we perceive colour varies depending on environmental lighting, so if you want to be particular you should use D50 or D65 lights in the room, especially if you're printing.

[misnome]

It depends on the calibration device you are using - some also take ambient light measurements to compensate.