London, Oct 30 (IANS) For people who experience "winter blues" when waking up early morning, a cure has been found. A British firm has invented an alarm clock that creates an artificial dawn.

Nearly one in four Britons suffer varying degrees of depression brought on by a lack of light during winters.

But Cambridge-based firm Lumie says its dawn simulator clock - Bodyclock Active - can help overcome the blues, the Daily Express reported.

"Simply set the time you need to be awake and choose your sunrise length - 15, 20, 30, 45, 60 or 90 minutes," a spokesman said.

"The light inside Bodyclock Active will gradually start to brighten up over your chosen sunrise length to provide you with your own personal sunrise. By the desired wake-up time, the light will be at its full brightness and you will have woken up naturally and gently, the way nature intended."

A person can also choose a dawn chorus of bird songs or rooster crowing.