Let's see....actually 14M ETH staked now so about 430K validators. Blocks are 12 seconds, so blocks per day is 24 * 60 * 5 = 7200. Taking 430,000/7200 gives 60 days.

But they're saying returns are more like 6%. Where are you getting return per block? (Also I think some of the return comes from doing block attestations, on every block.)