On Wednesday, 18 March 2020 14:06:50 UTC, Zaidy036  wrote:   
      
   > SET /A    
   > JDate=1461*(%Year1%+%Month1%)/4+367*(%MM%-2-12*%Month1%)/12-(3   
   ((%Year1%+%Month1%+100)/100))/4+%DD%-32075   
      
      
   Date algorithms written in the 20th century and containing integer division or   
   modulo operations may perhaps fail after the year 1999, if the arguments of   
   such operations then unexpectedly become negative.  A little over 20 years   
   ago, I spotted one such    
   trying to make its way into an Internet News and/or Mail standard, and pointed   
   out the imminent problem to the unsuspecting author - who expressed due   
   gratitude.   
      
   The one you quote may well be perfectly OK; but I advise testing all such   
   algorithms for all dates that they might be used for, AND for at least 400   
   full years.   
      
   I once found a browser in the last Windows version of which there appeared to   
   be a 3 where a 4 should be somewhere in its JavaScript leap-year rules.  It   
   would have worked well for current dates until about AD 2033.   
      
   --    
     (c) John Stockton, near London, UK.  Using Google Groups.           |   
    Mail: J.R.""""""""@physics.org - or as Reply-To, if any.             |   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)