Why 12 Hours?
You may have noticed most reflection based tokens have a similar cycle time of 60 minutes, some of them even have 30 minutes or 10 minutes. But they also carry similar issues: gas fees.
Gas Fees causing failed transactions
Imagine that for 10,000 holders that receives BNB each 60 minutes, the contract will have to issue 10,000 * 24 = 24,000 transactions a day. All of these transactions come up with an amount of gas fee and a low amount of BNB. Some of the BNB sent to a holder doesn't even pay for the gas fees.
Using a 12hr cycle, the contract is most likely to have all transactions successfully sent without major problems as the output will be sufficient to cover the gas fees, and the reward pool will be more fueled. If there are any issues, the team will be able to quickly resolve them. In addition, the number of BNB that will be sent will not be reduced. In reality, the output will be identical to that of the 60-minute cycle.
Another reason for the 12 hour cycle is to value true holders more than swing traders who buy for a pump and sell later. This will benefit all Futura holders in the long run.