Mideclipse timing residuals for USA‐ and RXTE‐observed eclipses of EXO 0748−676 during 1996–2000. The residual of the observed mideclipse time from a constant period of 0.15933781910 days and epoch of phase zero 46111.07418607 (MJD; TDB) is plotted as a function of the barycenter‐corrected observation date. The curved line is the constant‐period derivative fit to the RXTE and USA data from Table 4. The residuals appear grouped both above and below the ﹩O{\mbox{﹩-﹩}} C=0﹩ baseline. The measurement errors are significantly less than the systematic wandering in the mideclipse times as was found in Paper II.