Yes, they do. Berkshire always does them on a Saturday.  The earnings is said to be tomorrow, 5/3, so it'll probably be disclosed on Saturday.  This is also likely why Buffet is announcing this Amazon buying, since it coincides with their ER when their holdings will be released.

https://www.marketwatch.com/story/why-buffett-will-keep-berkshire-hathaway-reporting-earnings-during-the-weekend-2018-03-05

&gt;One way he plans to mitigate the perceived threat is to continue his practice of publishing Berkshire’s quarterly and annual results late on Fridays, after the markets close, or early on Saturday mornings. Buffett writes that this approach allows everyone to have maximum time for analysis and gives investment professionals a chance to develop “informed commentary” before the markets open again on Monday. 