In fact most advanced traders would argue the majority of the days in a year are not interesting enough to trade a selected instrument...
You can trade on those days all the same, but the market will be so unpredictable, directionless and efficient that the reward to risk ratios would not justify taking most of the trades that day (there are exceptions to this tendency for certain strategies)...
By diversifying the products you are covering, you can increase your trading frequency; however naturally this would often entail a lot more work, research and analyses on your part...