All The Births Are Recorded In Standard Time. Standard Time Is A Uniform Clock Time Used Throughout The Country, Based Upon The Local Mean Time Of A Certain Geographical Meridian Passing Through The Country And Arbitrarily Chosen By Law, For The Sake Of Convenience And Facility. All Watches And Clocks Are Accordingly Set To Show The Time.

Countries With Large Land Area And Several Meridians Passing Through That Country Will Have Different Local Mean Time Depending On The Longitude Of The Place. Therefore, The Time Of Birth Recorded From The Clock Is Not The Actual Time Of Birth.

Local Mean Time At Any Given Meridian Is The True Mean Time At All Places Which Lie On That Meridian, Irrespective Of The Latitude. Therefore, It Is Necessary To Convert The Standard Time (Clock Time) Into Local Mean Time. To Convert The Standard Time Into Local Mean Time Add (Or) Subtract 4 Minutes To Every Degree Of Longitude According To The Place Is In East Or West Of Standard Meridian. In India The Standard Meridian Is 82 Deg 30 Min East Of Greenwich.