We report a measurement of electron antineutrino oscillation from the Daya Bay Reactor Neutrino Experiment with nearly 4 million reactor νe inverse β decay candidates observed over 1958 days of data collection. The installation of a Flash-ADC readout system and a special calibration campaign using different source enclosures reduce uncertainties in the absolute energy calibration to less than 0.5% for visible energies larger than 2 MeV. The uncertainty in the cosmogenic 9 Li and 8 He background is reduced from 45% to 30% in the near detectors. A detailed investigation of the spent nuclear fuel history improves its uncertainty from 100% to 30%. Analysis of the relative νe rates and energy spectra among detectors yields sin 2 2θ13= 0.0856 ± 0.0029 and ∆m 2 32 = (2.471 +0.068 −0.070 )×10 −3 eV 2 assuming the normal hierarchy, and ∆m 2 32 = −(2.575 +0.068 −0.070 )×10 −3 eV 2 assuming the inverted hierarchy.