Someone correct me if I am wrong. But I am not convinced by people's interpretation of WARN here.
I found two versions of WARN by googling. One from federal and the other from state California.
Plant closings involving 50 or more employees during a 30-day period require notice. Layoffs within a 30-day period involving 50 to 499 full-time employees constituting at least 33 percent of the full-time workforce at a single site of employment requires notice. Layoffs of 500 of more employees are covered regardless of the percentage of workforce (29 USC, et seq., 2101 and 20 CFR 639.3).
Plant closings, layoffs or relocation of 50 or more employees within a 30-day period regardless of the percentage of workforce requires notice. Relocation is defined as a move to a different location more than 100 miles away (California Labor Code Section 1400 (c) and (d)).
But neither of them mentions 90 days. Also I heard cases where Oracle was able to overturn lawsuits by asserting that layoff happens actually 60 days later when the employees were removed from company. This means August 3rd layoff in ZFS group may not prevent Oracle from laying off people in August. Oracle law teams are really dangerously creative in interpreting WARN acts.
Reposted from @ONqWui9-1uai for good info.