UBS, which is battling weak earnings with cost-cutting, says it wants to give investment bankers more flexibility.
"You can't force people to work longer or shorter hours: people don't like being forced," said Orcel.
"All you can ask for is that they get their job done, but at the same time grant them enough flexibility...to find a balance that works for them."
Since May 4, junior and senior bankers working within the same team at UBS can use at least two hours per week for personal matters, as long as co-workers agree to cover for them.
"It's a 'give and take' exercise: People take two but also need to give two when their colleagues are away," said Orcel, who joined UBS in 2012, adding it should free up time for family events or activities like marathon training without any stigma.
"In an ideal world we wouldn't need this initiative, it would happen anyway. But for now having a branded initiative takes away the concern of finishing early or starting late."
UBS said 145 teams signed up to the plan in its first week.