The Nikkey Asian Review article Probe nears asteroid to unlock secrets to life's origins; Hayabusa2 mission includes return of samples after 18-month study begins:
TOKYO -- A Japanese space probe is just weeks away from reaching an asteroid thought to contain primordial matter from the formation of the solar system, cruising toward the start of an 18-month observational orbit that may offer insight into the origins of life.
The Hayabusa2 vessel has come within roughly 260,000km of the asteroid, named Ryugu, with arrival expected between June 21 and July 5, Yuichi Tsuda, the mission's project manager at the Japan Aerospace Exploration Agency, said Thursday. The probe has enjoyed a smooth journey since its launch in 2014. (emphasis added)
The asteroid Ryugu will reach its ~0.96 AU perihelion in the first week of June, 2018.
Could JAXA's Hayabusa2 mission project manager really not know when Hayabusa2 will arrive at it's destination to better than a two week window? For comparison, see the BBC News article Apology after Japanese train departs 20 seconds early.
Is this an editorial oversight, or will the final arrival date be adjusted by propulsive maneuvers, or is the arrival time in fact not known for some other reason?