Washington, February 18:

Americans turn their clocks forward three weeks early this year, raising the specter of glitches for global business, travel and other functions in a scenario raising comparisons to the ‘Y2K’ bug.

Daylight savings time begins the night of March 11-12 for the first time, instead of the first weekend of April, as has been customary. The change was mandated by the Energy Policy Act-2005, and is aimed at reducing needs for lighting and other energy costs.

The clock change will be the second Sunday in March instead of the first Sunday in April, and end on the first Sunday in November instead of the last Sunday of October. For some, the early shift may be a mere inconvenience of manually resetting clocks, older computers or video cassette recorders. But it also poses problems for global airline schedules and a host of computerised functions that require updates.