The truce began on Tuesday across the war-torn country, with the United Nations acknowledging there has been a signficant reduction of violence.
Attention also turns to the delivery of desperately needed humanitarian aid to besieged areas.
Despite heavy scepticism prior to its commencement, a cessation of hostilities in Syria is largely holding, 24 hours after it came into effect.
The long-negotiated ceasefire requires government forces and rebels to halt all attacks, and will be renewed every 48 hours.
Militants from the self-proclaimed Islamic State and Jabhat Fateh al-Sham, formerly al-Nusra Front, aren't part of the ceasefire agreement.
Activist groups say no civilian deaths have been recorded in the first 15 hours.
The United Nations special envoy to Syria says he is satisfied there has been a "significant drop" in fighting.
But Staffan de Mistura acknowledges the truce had a shaky start.
"This is only 24 hours. The 48 hours benchmark is going to be important, because that's the one which will be assessed by the two co-chairs regarding the cessation of hostilities which they agreed upon on Friday."
Those co-chairs are the United States and Russia, who finally struck a deal after months of failed talks.
If the truce holds for seven days, both countries will coordinate their air strikes on militant groups.
However Russia, which supports the Syrian government, has already accused US-backed rebels who oppose President Bashar al-Assad of violating the truce.
Lieutenant General Viktor Poznikhir claims the Russian military registered 23 cases of shelling by rebels in the first 12 hours of the ceasefire.
"Syrian governmental troops have completely stopped fire except in the areas where ISIS and Jabhat al Nusra rebels are operating. Unfortunately, the same cannot be said about moderate opposition armed units controlled by the USA."
Russia claims fighting was recorded in suburbs surrounding northern Aleppo, but that has not yet been substantiated.
The besieged city in what was Syria's most populated region has been the most devastated by the five-year civil war.
Locals say that, for the first time in years, Aleppo's streets and skies are quiet.
"Thank God, all is well and people are coming out to the streets. Thanks and praise to God. No planes in the skies. We have heard none since this morning."
Staffan De Mistura says if the truce holds, focus will be on coordinating UN aid convoys to Aleppo's rebel-held areas.
"What is our priority? Eastern Aleppo, no doubt. Because they've been isolated long enough. Now trucks are ready for that, but what is missing still is the famous authorisation letters from the government. We are asking them to issue them very quickly so we can all of us take advantage of this reduction of violence in order to be able to make sure that not only eastern Aleppo, western Aleppo, but everywhere else, convoys can start moving."
Dozens of aid trucks have started to cross into Syria from the Turkish border, headed for other besieged areas.
But it currently remains unclear how far into the country they will go.
While there are signs of progress, the UN Human Rights Commissioner has lamented over what has been lost since 2011.
Zeid Ra'ad al Hussein condemned the Syrian government for human rights abuses, saying it was one of five countries that routinely refused to cooperate with investigators.
"This is a state led by a medical doctor, and yet it's believed to have gassed its own people, has attacked hospitals and bombed civilian neighbourhoods with indiscriminate explosive weapons, and maintains tens of thousands of detainees in inhuman conditions. Words cannot convey how profoundly I condemn this situation."
Russia wants to release the full details of the agreement to the public, but the US is against that idea.
Foreign minister Sergey Lavrov says Moscow has "nothing to hide".
"It should help to regulate the Syrian crisis in the context of solving anti-terrorist tasks and improving the humanitarian situation, strengthening the ceasefire for participants of the truce deal - terrorists naturally not being a part of it. All of this should create grounds for re-establishment of an inter-Syrian political process, something we can't drag out any further."
