/// <summary>Converts the parameters to a constant date expression </summary>
/// <param name="expr">The function call expressions</param>
public object ToConstantDate(BindingCallExpr expr)
{
var month = Convert.ToInt32(expr.ParamList[0]);
var day = Convert.ToInt32(expr.ParamList[1]);
var year = Convert.ToInt32(expr.ParamList[2]);
var time = (string)expr.ParamList[3];
var token = expr.ParamList[4] as TokenData;
return(Exprs.Date(month, day, year, time, token));
}