Gold futures active months are: Feb, Apr, Jun, Aug, Oct, Dec
https://www.cmegroup.com/markets/metals/precious/gold.quotes.html
Monthly contracts listed for 3 consecutive months, any Feb, Apr, Aug, Oct in the nearest 23 months and any Jun and Dec in the nearest 72 months
Primary gold futures contracts are February, April, June, August, October, and December.
Futures Volume and the Options Volume
Futures Close-Out Policy (IB) type in symbol in search bar GC or MGC
GC and MGC TERMINATION OF TRADING: Trading terminates at 12:30 p.m. CT on the third last business day of the contract month.
Example: The December2020 contract actually only expires on the 29-th of December. But the front or active month (the month where most of the volume is) moved to February2021. But IB does not allow new long positions in December2020 contract and liquidated all long positions the 26-th of Nov 2020. Strangely they will not liquidate the short positions.
But with oil it is different. The active contract on oil is now the January2021 contract. However, this contract will expire at the end of December 2020 and then will no longer trade.
Total above ground stocks are below 200,000 metric tons according to most experts. Each year, global gold mining adds approximately 2,500-3,000 metric tons to the overall above-ground stock of gold. The average concentration of gold in Earth’s crust is estimated to be between 0.0011 ppm(source) and 0.0031 ppm(source). Which leads to an estimate of 122 billion metric tons in the Earth's crust (top 4km). Therefor, potentially there is still a huge amount of gold on earth. The small amount of gold we have mined to date suggests however that access to the gold is not easy and certainly not cheap. It is therefor not very useful to give a number on how much gold there is still out there for us to mine. It is a huge amount if we only could get our hands on it at the current costs.