According to CNBC, the house of Representatives postponed its meeting because a memorial service for the late Representative John Lewis will be held in Washington on the same day.
Cook, alphabet and Google CEO Sundar Pichai, Facebook CEO Mark Zuckerberg and Amazon CEO Jeff Bezos were all scheduled to testify to the house antitrust Sub Committee on Monday.
The meeting aims to end months of bipartisan investigations into four major technology companies. It is trying to determine whether these companies are using their power to stifle market competition.
Apple has been censored for issues such as its app store business, third-party app sherlocking and the management of parental control apps.
After the testimony of technology executives, lawmakers are expected to publish a report on the findings of the investigation, as well as proposals for new antitrust regulations. Although the report was originally scheduled for release in April, the covid-19 pandemic has delayed this schedule until some time in the autumn.