anchor.diff:  
   function PreciseTimeToStr(const APreciseTime: TPreciseTime): string; inline;
   begin
  +  Assert(APreciseTime > 0);
     Result := FormatDateTime('yyyy-MM-dd hh:mm:ss.zzz', PreciseTimeToDateTime(APreciseTime));
   end;
   
  
positive.code:       end;
  
        { Collect all the rules for the year we're looking for. }
        if (YearOf(LStart) <= AYear) and (YearOf(LEnd) >= AYear) then
        begin
          { Load the rules for this year. }
          LRules := GetPeriodRulesForYear(LPeriod, AYear);
  
negative.code:   LYMinus1, LYPlus1, LR, LSk: TObservedRule;
  begin
    { Mark all intermediary data as un-initialized. <-- this is date ZERO which is the start point. }
    LStart := 0;
  
    LYMinus1.FPeriod := nil;
    LYPlus1.FPeriod := nil;
  