The temporary ceasefire in Gaza and hostage-prisoner release is now expected to start tomorrow, a day later than originally announced.

The deal would see the exchange of hostages held by Hamas for Palestinian prisoners being held by the Israelis during a four-day ceasefire in Gaza.

One of the mediators says the delay is to create “appropriate conditions” for the swap and ceasefire.

Renan Levine, a professor in the Dept of Political Science at the University of Toronto, says the agreement is really a series of one-day pacts but it wouldn’t take much to create a situation where violence once again erupts. He says anyone who decides they don’t like the situation can interfere—and Hamas is not the only militant group in the region.

He notes that Israelis don’t have proof of life for almost all of the hostages. As well, there may be an expectation that certain hostages will be released but that doesn’t happen, and you already have hundreds of armed soldiers walking around—so it can go wrong in many ways.

Qatar’s Ministry of Foreign Affairs says the temporary ceasefire will begin at 7 a.m. local time in Gaza.