I think it would be “you need to join Euro within 5 years”, but there are no sanctions for your currency being too unstable for 0.1 % of the time and you thus being refused admittance to the Eurozone. The admittance must be refused under those circumstances – according to the current rules. They can.of course be changed, but that will then affect everyone, including Poland, UK, Czechia and Sweden (but not Denmark, because it has been relieved of that requirement).
I think it would be “you need to join Euro within 5 years”, but there are no sanctions for your currency being too unstable for 0.1 % of the time and you thus being refused admittance to the Eurozone. The admittance must be refused under those circumstances – according to the current rules. They can.of course be changed, but that will then affect everyone, including Poland, UK, Czechia and Sweden (but not Denmark, because it has been relieved of that requirement).