  We establish that global solar p-mode frequencies can be measured with
sufficient precision on time scales as short as nine days to detect
activity-related shifts. Using ten years of GONG data, we report that mode-mass
and error-weighted frequency shifts derived from nine days are significantly
correlated with the strength of solar activity and are consistent with long
duration measurements from GONG and the MDI/SOHO instrument. However, the
correlation varies from year to year and appears to be a complex phenomena. For
the short-duration observations, the analysis indicates a higher sensitivity to
activity. We also find that magnetic indices behave differently in the rising
and falling phases of the activity cycle.
