We report an experimental demonstration of temporal ghost imaging in which a digital micromirror device (DMD) and +1/-1 binary modulation have been combined to give an accurate reconstruction of a nonperiodic time object. Compared to the $0/1$ modulation, the reconstruction signal can be improved greatly by +1/-1 binary modulation even with half of the measurements. Experimental results show that 0/1 binary temporal objects up to 4 kHz and sinusoidal time objects up to 1 kHz can be reconstructed by this method. The influences of modulation speed and array detector gray levels are also discussed.