The government imposed new nationwide closing times Saturday for stores, restaurants and cafes, ordering them to shut early.
"It's ruinous," said Youssef Salah, a cafe owner in Cairo.
"It deprives us from our peak time."
The decision is one of a series of measures the government has taken in recent weeks to mitigate the fallout of the US and Israeli war against Iran, which has shaken the Middle East and the global economy.
Though Egypt is not a party to the widening conflict, the most populous Arab country is one of the most impacted by the war's far-reaching repercussions, including higher oil prices and disrupted shipping routes.
The early closures will have dire repercussions on hundreds of thousands of small businesses found on almost every street, alley and lane across the country.
Some of them — including many eateries, juice shops and cafés — usually operate nonstop.
Salah, the café owner in Cairo's middle-class neighbourhood of Sayeda Zeinab, said he was forced to cut his 35-member workforce by 40 per cent.
The 46-year-old father-of-three used to keep his venue open 24 hours a day, with peak hours starting in the evening till the first hours of the new day.
The late-night shifts are now abolished, he said.
"It's painful," Salah said as he closed his shop doors at 9pm (local time) on Saturday.
Yet two days into the decision, some Egyptians danced around the government order.
Some cafes closed their front doors as patrons inside went about smoking shisha or playing chess, dominos or cards.
Some took to social media sarcastically to criticise the decision for depriving Cairo of its nightlife.
"The Butterfly effect," Mahmoud Elmamlouk, editor of a local outlet wrote on social media after cafe shops shuttered their doors Saturday evening.
"The closure of Strait of Hormuz has deprived us from smoking shisha."
Ayman Harbi, who works at a store in downtown Cairo, called on the government to extend the opening hours at least till midnight, saying that closing at 9pm is "extremely difficult" for business like his.
"Our work in the summer usually starts after 8pm," he said.
"Forcing me to close at 9pm makes the workday pointless."
Magdy al-Deeb, a business owner, urged the government to reverse the decision to preserve jobs, especially for cafes and small businesses.
"Where will all those people (workers) go," he asked of those who could lose their jobs.
Smoking a shisha — the tobacco burning water pipe — in a Cairo café, he said society "must protect people's livelihoods".
The decision to close businesses early has also changed the lifestyle of Egyptians accustomed to being able to buy virtually anything at any time, especially in big cities like Cairo and Alexandria.
A night time tour across Cairo Saturday and Sunday revealed the city's usually vibrant streets turned eerily quiet.
Shops, restaurants, malls and cafes across the country have been ordered to close at 9pm for a month.
The measures -- described by the government as "exceptional" — include dimming streetlights and roadside advertising.
The government exempted tourist-attraction areas from its energy-saving measures, given that tourism is a major source of foreign currency for the cash-strapped country.
The exempt areas include the Red Sea tourist resorts of Hurghada, Sharm el-Sheikh, Marsa Alam, as well as the antiquities-rich southern cities of Aswan and Luxor.