If implemented, the regulation could become an issue in parliamentary elections now expected early next year, as parties try to appeal to small businessmen and their employees angry over the early closing hours.
"This regulation is a huge mistake," said Ashraf Shaaban, who runs a falafel sandwich in Imbaba. "It is against the nature of the Egyptian people. We stay up late. We don't want a curfew."
As he quickly whipped up sandwiches for a line of customers, he added: "If men spend their evenings at home rather than at cafes, the population will grow. There will be more babies."
"Morsi is insulting the people!" shouted one of his customers.___ Associated Press correspondents Sarah El Deeb and Lee Keath contributed to this report.