Open all of the time, along the pedestrian zone south of Piazza della Repubblica towards Palazzo Pitti
Built very close to the Roman crossing, the Ponte Vecchio, or Old Bridge, was the only bridge across the Arno in Florence until 1218. The current bridge was rebuilt after a flood in 1345. During World War II it was the only bridge across the Arno that the fleeing Germans did not destroy. Instead they blocked access by demolishing the medieval buildings on each side. On November 4, 1966, the bridge miraculously withstood the tremendous weight of water and silt when the Arno once again burst its banks.
It is also possible to admire the bridge from underneath in theater presentations, the occasional concert and boat rides. After the disaster in 2016, there is talk of turning the work road constructed during the rebuilding of the river walls int a park area, where it will be possible to stroll the river banks and get a close-up view of the bridge.
https://www.visitflorence.com/florence-monuments/ponte-vecchio.html