grand inquisitor activity

Hello, I have an off-topic question. How often does grand inquisitor activity happen?
Is there a calendar or place that states this

there is nothing that states when it will come back besides being fully there after 1 year of the initial release. we can only go by the precedent of past events that were similar, thus about 3-4 months before it first returns. we are at 84 days currently or almost 3 months so it should return by end of October, if the precedence followa.

Thanks

Another necro?