The nearest expiration date for E-mini Russell 2000 Index Futures (Dec 2020) is Dec 18, 2020.
The best time to sell a futures contract is when you've already made money on the investment, but still have plenty of time left before the expiration date. Thus, a good option would be to sell E-mini Russell 2000 Index Futures (Dec 2020) before Dec 18, 2020.