Under Article 19(11) of the UK Market Abuse Regulation (UK MAR), the period of 30 calendar days before the announcement of an interim financial report or a year-end report that an issuer is obliged to make public according to the rules of the trading venue where the issuer's shares are admitted to trading or the law of the United Kingdom, during which a person discharging managerial responsibilities of an issuer is prohibited from conducting any transactions on its own account or for the account of a third party, directly or indirectly, relating to the shares or debt instruments of the issuer or to derivatives or other financial instruments linked to them.

Note that the announcement of preliminary financial results agreed by the management body of the issuer constitutes the announcement marking the end date of the closed period where those preliminary financial results contain all the key information relating to the financial figures expected to be included in the year-end report (see section 2 of ESMA: Questions and Answers on the Market Abuse Regulation).

For more information, see Practice note, UK MAR: PDMR transactions: Transactions during closed periods.

Note further that a "closed period" is also defined in EU MAR, which applied in the UK before the end of the UK-EU transition period. For more information, see Practice notes, EU Market Abuse Regulation (EU MAR): overview and EU MAR: PDMR transactions: Transactions during closed periods.