@Nsk143 wrote:
I am been member since 2015 but start using since I activate my line again last month.
Congrats on ranking to town hero!
For the community ranks, the time counts from when you registered to the community, not from your service activation. Normally, town hero is achieved at 4 months after community registration, provided you accumulate a minimum number of posts/bravos/solutions. The exact minimums are uncertain, but see here for the latest estimates. You had previously been inactive (not accumulating stats) for much of the time since registration, which is why you just ranked up now with your recent activity.
