Cricket: What are the rules about bad light in Test matches?

In Test cricket, play cannot start, is immediately suspended, or cannot restart if the on-field umpires agree the light conditions are “dangerous or unreasonable”.

That wording comes from section 2.8 of the International Cricket Council’s Test match playing conditions, which states the decision on whether lighting is unsafe is solely down to the umpires, following consultation with the ICC match referee.

Umpires are allowed to use light meters, which must be supplied by the ICC, as a guideline to determine whether light is fit for play or is improving or deteriorating. Light meters must be uniformly calibrated.

When natural light has worsened to a level deemed unfit for play, the umpires will authorise the ‘ground authority’ – those responsible for hosting the match – to use any available artificial lighting so play is able to continue in acceptable conditions.

Should artificial lighting at the ground not work, rules on natural lighting and weather will apply.

For day/night Test matches, the home cricket board will decide the latest times at which the floodlights are to be switched on prior to the start of a day’s play, and must inform the match referee.

Once play is suspended, it is the responsibility of the match umpires to continue to monitor conditions.

This article is the latest from BBC Sport’s Ask Me Anything team.