Advantages of DST (Daylight Saving Time):-
o DST take advantages of summers extra daylight hours. Clocks are put forward 1 hour (Usually in spring, thus gaining an hours sunlight during conventional waking hours.
o The practice was first suggested, half
seriously in 1784 in an essay by an American Statesman & scientist Benjamin Franklin.
o It was not until 1st world war, that several countries including Australia, Britain, Germany, & US adopted DST as a means of conserving energy resources.
o Besides energy conservation the other benefits are
 Increase leisure time
 Safer journeys for school children.
o In the northern Hemisphere many countries like the US begin DST towards the end of March and resume Standard Time towards the end of October. (Spring Forward fall back (Autumn)}
o In the tropical belt, the lengths of day and night change little seasonally and there is not much twilight. Consequently, DST will offer little or no savings for tropical region.
o DST is based on two geographical facts.
 The seasonal variation in the length of the day increases towards the poles. The summer day become much longer in higher latitudes.
 The duration of dawn of twilight or is primality a function of latitude. (Duration of down & twilight increase towards of Pole)
o Last observation, generally the watch is shifted to 1 hour but implicitly, one can go for more than one hour, in the past at certain period of crisis and
some countries go for 2 hours also. But in the present times, the practice is limited to 1 hour.

Jet Lag:-
o The effect of sudden switch of Time zones in a travel, resulting in tiredness, and getting out of step with Day & Night.
o Advice from Doctor
 Rest for 1 or 2 Day and body will get frequency match
 Like Crew Member, Statesman of World, Politicians like Modi, Business Executives.
 Hormones melatonin is injected for treatment which is usually released at night during sleep.

Circadian Rhythm
o Metabolic Rhythm found in most organisms which generally coincides with 24 hours day. It’s most evident manifestation is a regular cycle of sleeping and waking.
 Nature want to sleep us at a particular time and
also wakes up at a particular point of time.