The period runs from the moment of becoming aware and, in practice, should be managed in calendar days. That is why the response plan is built to cover weekend and holiday scenarios as well.
One relief valve is built into the rule: if you do not yet have the full picture, an initial notification can be filed on time and supplemented as facts emerge, rather than missing the deadline while you investigate. The plan should define who confirms “awareness,” since that moment starts the clock.
Shall we apply this matter to your situation?
Tell us your specific situation in a few sentences; we'll assess it with the right team.