London:International Cricket Council president David Morgan will be "surprised and disappointed" if day-night Tests aren't introduced within two years.
The ICC hopes the move would increase crowds in parts of the world where the five-day game's popularity is on the wane.
Morgan said on Wednesday that Test cricket should always be the "pinnacle of the game."
"In some countries Test cricket is not that popular in terms of people paying at the gate," he said. "If you look at a country like Australia with big stadia and very hot conditions, it's made for day-night Test cricket.
"Eighteen months ago I wouldn't have been overly enthusiastic about this, thinking of tradition and records, but test cricket has changed over 130 years and there are now very good reasons for bringing crowds out. I'd be surprised if we don't see day-night Test cricket within the next two years - surprised and disappointed."