Glamorgan have accepted an England and Wales Cricket Board request to play with a pink ball in their final County Championship match at Kent.
Kent had also accepted the experiment for the four-day match, starting in Canterbury on 12 September.
The Division Two match will begin at 1400 BST, instead of 1030 BST, and finish at 2100 BST.
A pink ball has already been tried in first-class cricket in Pakistan.
The move is part of an International Cricket Council proposal to introduce day-night Test matches.
And the ICC is keen for all Test-playing nations to use the new ball in their four-day competitions to ensure it is up to the required standard.
The viability of playing day-night Tests, to boost crowds, is being explored by the game's governing body.
In June, England and Wales Cricket Board managing director Huw Morris said he was "open-minded" about the prospect of playing floodlit Test matches.
The former Glamorgan batsman said: "The colour of the ball we would potentially use under lights would be important and trialling it in other forms of the game before we do it at international level would be important."
Both Glamorgan and Kent are out of contention for promotion from Division Two of the County Championship.