Time difference between the newly calibrated GOLF data and the l = 0 GONG data as a function of time; (top) unshifted GOLF data; (bottom) shifted GOLF data according to Table 2 computed using a 10-day integration window (black dots) or a 45-day integration window (green dots). The median value of the time shift for the corrected time series is 47.3 s. About 99.8% of the corrected values are within 5 s of this median value.