Could you please clarify for me the duration of holding futures on Binance? I'm interested in understanding the flexibility of this platform, and I'm wondering if there's a limit to how long I can keep my futures positions open. Could you explain how Binance manages the holding period for futures and if there are any specific timeframes or deadlines I should be aware of? Additionally, I'd like to know if there are any associated costs or penalties for holding futures for an extended period. Thank you for your assistance in clarifying this matter.