I think all the grounds have access to lighting, whether it's permanent or 'bussed in' for the occasion.

As far as I'm aware, the rule is that, when the lights are on, if shadows are visible on the pitch then the umpires have to offer the light. This allows the ludicrous situation of the umpires being forced to offer the light when they think it is still easily playable. Another problem is that lights are not all the same. Some are more pwerful than others, and grounds are different sizes, so shadows might appear earlier from one ground to the next.

Basically, the whole thing is a mess. The judgement on the light should be left to the umpires, without reference to shadows on the pitch. I think that artificial lighting for test matches isn't needed anyway. It's benefit is dubious, and we'd know where we stand if we left the lights off until the day night ODIs.

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Just what is going off out there?