Hi, it is easy to calculate how often a node will get a block reward on average. There are about 3,500 to 4,000 blocks every day, shared by the number of nodes. If, say today, there are 100,000 nodes. Then each node will get one block reward (11 NKN) every 25-30 days, on average.
Again I want to emphasize “on average”. Because each node will be different, and statistically the interval between each block reward can be dramatically different. And also the Internet speed and latency of the node will have impact on the mining reward as well.