New Delhi, May 27 -- Ever found yourself out of sync with normal sleep patterns after late nights or working a night shift? It could be you're experiencing what scientists call social jet lag.

The term describes the misalignment between our internal body clock (circadian rhythm) and our social schedule.

Social jet lag associated with irregular sleep patterns and inconsistent exposure to daylight is increasingly common, and has been linked with a weakened immune system.

Disruption of our circadian rhythms through shift work, for example, has been shown to have a negative impact on our ability to fight infections.

These observations reinforce the idea that maintaining a robust circadian rhythm through regular exposure to daylight suppo...