The periods for which interim financial statements are required can vary depending on the accounting standards and regulations applicable to the company and the requirements of the stock exchange where the company is listed. However, in general, interim financial statements are required to be prepared and presented for the following periods:

1. Quarterly: In many jurisdictions, companies are required to prepare and present interim financial statements on a quarterly basis. This means that the reporting period would cover a period of three months.
2. Half-Yearly: In some jurisdictions, companies may be required to prepare and present interim financial statements on a half-yearly basis. This means that the reporting period would cover a period of six months.
3. Other Periods: In some cases, companies may be required to prepare and present interim financial statements for other periods, such as nine months or any other period that is shorter than a full fiscal year.

It is important for companies to comply with the applicable regulations regarding the preparation and presentation of interim financial statements, and to ensure that the interim financial statements provide accurate and timely information to stakeholders.