Sri Lanka [Images] will put back its clocks by half an hour and revert to the practise of having the same standard time as India after its 10-year experiment to save daytime failed.

President Mahinda Rajapakse said the country will revert to its original standard time, five and a half hours ahead of Greenwich Mean Time, which the country maintained till May 1996.

"The change will take place from the Tamil and Sinhala New Year on April 13," the state-run SLBC radio said. "The president made the order after complaints from parents that school children were inconvenienced by the new time."

In May 1996, the then government advanced the clock by an hour and by October that year brought it back by half hour to put Sri Lanka six hours ahead of GMT.

The advancing of the clock in 1996 was rejected by Tamil Tiger rebels who control large parts of the island leading to two time zones within the island.

Sri Lanka reverting back to its old time zone would have implications for astrologers, computers, airline schedules and Microsoft whose latest Windows versions give Sri Lanka standard time as six hours ahead of GMT.