<p>The first dawn of 2017 will come a second late as India will join the rest of the world to add “one leap second” to its official time on the morning of January 1.<br /><br /></p>.<p>To account for earth’s slowing rotation around its own axis, time-keepers periodically add a leap second to universal time so that clocks remain accurate.<br /><br />The adjustment is critical for applications like satellite navigation, functioning of communication networks, for tech companies and those conducting astronomical measurements.<br /><br />As the leap second is added simultaneously across the world at UTC (Coordinated Universal Time) 23:59:59 hrs on December 31, 2016, New Delhi-based National Physical Laboratory (NPL), which maintains the Indian Standard Time will count up the additional second at 05:29:59 hrs on January 1, 2017. This is because the Indian Standard Time is 5.30 hours ahead of UTC.<br /><br />“Last time, we did this on June 30, 2015. We do it time to time as per the international norm,” A Sengupta, who heads the time and frequency division at NPL told DH.<br /><br />The earth’s rotation slows down due to several factors, including the moon’s gravitational pull.<br /><br />The earth’s speed of rotation around its axis increases and decreases from time to time. This leads to a mismatch between Astronomical Time and the UTC maintained by a series of 300 highly precise atomic clocks, including the one at NPL.<br /><br />The leap second adjustment is to correct the mismatch. Since 1972, 26 leap seconds have been added in intervals varying between six months and seven years.</p>
<p>The first dawn of 2017 will come a second late as India will join the rest of the world to add “one leap second” to its official time on the morning of January 1.<br /><br /></p>.<p>To account for earth’s slowing rotation around its own axis, time-keepers periodically add a leap second to universal time so that clocks remain accurate.<br /><br />The adjustment is critical for applications like satellite navigation, functioning of communication networks, for tech companies and those conducting astronomical measurements.<br /><br />As the leap second is added simultaneously across the world at UTC (Coordinated Universal Time) 23:59:59 hrs on December 31, 2016, New Delhi-based National Physical Laboratory (NPL), which maintains the Indian Standard Time will count up the additional second at 05:29:59 hrs on January 1, 2017. This is because the Indian Standard Time is 5.30 hours ahead of UTC.<br /><br />“Last time, we did this on June 30, 2015. We do it time to time as per the international norm,” A Sengupta, who heads the time and frequency division at NPL told DH.<br /><br />The earth’s rotation slows down due to several factors, including the moon’s gravitational pull.<br /><br />The earth’s speed of rotation around its axis increases and decreases from time to time. This leads to a mismatch between Astronomical Time and the UTC maintained by a series of 300 highly precise atomic clocks, including the one at NPL.<br /><br />The leap second adjustment is to correct the mismatch. Since 1972, 26 leap seconds have been added in intervals varying between six months and seven years.</p>