“Potential days mining” is an estimate based on first and last seen dates at the time of snapshot. This inaccurately assumes the address mined the entire date range. Some did and some did not. These dates can be used for identifying potential address changes by a solo miner or pool operator. One address may stop getting mined to and is last seen on a specific day and a new one is first seen on the same day or days later. There are multiple early addresses that mined large supplies in a matter of days or weeks.