A transaction could have a timestamp and further, a block always has a timestamp. The "rewards" rule is that for eligible utxo, the utxo value is increased when it is spent, so X looks like X+R. To be eligible, it needs to be more than an hour old, have nLockTime in the tx set. To be a valid timestamp, the times between the current block and the utxo's nLockTime are subtracted and divided by 60 to convert it to minutes. If it is more than one month's worth of minutes, it is set to one month's worth of minutes. (this mechanism caps the most amount for R at 5% for a year if claimed monthly).
The number of minutes is used to prorate the value of R to be 5% per year, so if 1 month, then it is 5/12 percent, since there are 1 months in a year for all transactions the value of X+R is used as the value of all the inputs, which means that if you spend all of X, there will be R leftover (ignoring txfee)you can check that nLockTime is set via the block explorer by looking at the nLockTime field t also needs to be for more than 10 KMD. The coins don't exist in any specific wallet, they are in the blockchain. wallets are just ways to access the coins: the coins come from "thin air", they just exist because all nodes agree that they do. It is part of the 200 million total coins as 5% compounded over 14 years is about double.The txfee is 0.0001 unless it is a very large tx.
In the event O is the same as X, that means the txfee is R, eg. unclaimed rewards (utxos) never disappear until they are spent. Rewards once accrued don't go down as "minutes since nLockTime" never goes down, only up.