Darn. You're right. The free data is now shifted two months in advance rather than one. The root cause of the bug was here:
YCharts Fundamental Data for Securities and Economic Data provider, posts #110-112
In short, back in March 2017 it was noticed that the earnings dates for some companies were still being reported as non-delayed. Now it turns out that the fix I made has been erratically shifting the
already adjusted dates in the "free" data client.
After all the years, YCharts still got the dates in post #110 wrong e.g.
Symbol Date (YCharts) Date (Zacks)
AVGO Oct. 31, 2016 Dec. 8, 2016
COO Oct. 31, 2016 Dec. 8, 2016
Sadly, the fix has made it worse for many other stocks like CNMD. I have no idea about the proportion of stocks with incorrect and correct earnings release dates at YCharts as there's no good solution to bad data. :/ The fix will be reverted in v2020.10 and if you'll be still using the free data by then, it will has to be reloaded by updating it.
P.S. The paid data by YCharts hasn't been affected.