If North Korea does close the Yongbyon nuclear reactor down in late July, that will be over three months past the date agreed upon by the 13 February deal (14 April), not that timelines appear to be that sacred anymore:

North Korea plans to seal its main nuclear reactor and source of weapons-grade plutonium in the second half of July… “To stop the reactor, it will take about a month according to our specialists… So we are counting on sealing it (the reactor) in the second half of July, in accordance with the agreements reached at the six-party talks,” the source said.

[. . .]

South Korea has contacted at least two refiners to supply North Korea with 50,000 tons of oil pledged to Pyongyang if it started to shut the Yongbyon nuclear plant located about 100 km (60 miles) north of Pyongyang, industry sources said in Seoul said on Monday.

It’s worth noting that this is the same shipment of oil that Seoul prepared for shipment in April, only to be cancel the contracts for shipment with North Korea failed to shutdown the Yongbyon reactor as agreed. ROK taxpayers shouldn’t be happy:

The cost of borrowing the tanker and other expenses have meant a loss of some W3.6 billion (US$1=W929). Seoul is wasting W100 million a day due to expenses incurred from the pre-purchase of the oil and the hasty lease of the tanker.