public static void Main()
Console.WriteLine(long.MinValue ) ;
Console.WriteLine(long .MaxValue ) ;
Console.WriteLine( sizeof (long) ) ;
Console.WriteLine( default (long) ) ;
Console.WriteLine( typeof (long) ) ;
a = (long) 60 * 60 * 24 * 365;
Console.WriteLine(TimeSpan.FromMilliseconds(a) ) ;
Console.WriteLine(DateTimeOffset.FromUnixTimeMilliseconds( 1597700921860 ) ) ;
var posixTime = DateTime.SpecifyKind(new DateTime(1970, 1, 1), DateTimeKind.Utc);
var time = posixTime.AddMilliseconds(1597700921860);
Console.WriteLine(time) ;