Specifically note this information from the above-linked Wiki:
Challenges begun before June 16 of a given year earn status for the remainder of that year and the first two months of the following year (8-14 months total); challenges begun on or after June 16 grant status for the remainder of that year, the following year, and the first two months of the year after (14-20 months total).
I'm not sure what is lacking in clarity here.
Cheers.