The Islamist movement and Israel began observing the five-hour ceasefire at 0700 GMT, after 10 days of violence that has killed at least 230 Palestinians and one Israeli.
And hours later the ceasefire appeared to be holding despite reports that three mortar rounds fired from Gaza hit southern Israel.
The people of Gaza City immediately took advantage, taking to the streets in their cars and forcing police to try to negotiate the traffic jams that suddenly formed.
And outside banks in the city, crowds of hundreds of people massed on ATMs, eager to withdraw money to buy supplies before the five-hour truce ends at 1200 GMT.
"I've been borrowing money from people to get by, and now I'm going to be able to pay them back," said Abdul Qassam Ataneh, waiting outside a branch of the Bank of Palestine.
"The truce is a chance for people to get out of their homes and get money and supplies.
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"Ramadan comes with a lot of expenses," he added, in reference to the ongoing Muslim month of fasting.
But two and a half hours into the truce, three mortar rounds were fired from Gaza into the southern Israeli region of Eshkol, the Israeli military said.
There was no immediate claim of responsibility from militants in Gaza.
Before the mortar attack, Mohamed Nasr said he was happy with the brief truce, but wished the hours were longer.
"It's not enough. People need to go out and get supplies and to get their belongings. It should have been from 7:00 am until dusk," he told AFP.
"We've been stuck in our houses during this war, because of the violence. It's like living under curfew."