Call-Date-in-WL7

Hello.
I have a strategy developed in Wealth Lab 6.9 in which one of its functions is to buy on certain dates.
So far, in version 6.9 this line of code worked fine for me:

CODE:
if (Bars.Date[bar].Month == 7 && Bars.Date[bar].Day == 15)
   {
   BuyAtClose(bar-1, "Buy Date");
   }

I have tried to adapt it as follows to Wealth Lab 7 but it gives me an error because it does not recognize "Date":

CODE:
public override void Execute(BarHistory bars, int idx)
      {
         int bar = idx;
         Position foundPosition0 = FindOpenPosition(0);
         bool condition0;
         if (foundPosition0 == null)
         {
            condition0 = false;
            {
               if (bars.Date[bar].Month == 7 && bars.Date[bar].Day == 15)
               {
                  condition0 = true;
               }
            }
            if (condition0)
            {
               _transaction = PlaceTrade(bars, TransactionType.Buy, OrderType.Market, 0, 0);
            }
         }

What is wrong in the line "if (bars.Date[bar].Month == 7 && bars.Date[bar].Day == 15)" for WL7?