Not sure that makes any sense, maybe he meant 60 days before the PDUFA Date they need to have the Adcom by? If they gave Amarin 60 days notice on July 29 they would then have the Adcom on the day of the PDUFA Date?
Of course he adds "Practically speaking, it would have to be well before that. " so he's just doing simple math and trying to say if they have an Adcom before the PDUFA Date mathematically it mush be no later than 60 days before the PDUFA date.
It's kind of a dumb tweet because he ignores the need to have time from the Adcom to the PDUFA Date. And his 60 days notice for an Adcom is not supported by other Adcom's that have gone as little as 30 days from announcement to Adcom.
So to sum it up AF was drinking heavily before that tweet.
From our end I think the end of June is a solid cutoff, if nothing this week no Adcom seems pretty close to 100%. I guess theoretically they could announce July 15 for Aug 14 Adcom and be within the 30 days notice and about 6 weeks from PDUFA but seems unlikely they would make everything that tight and give notice that late.