Casio SP-400G

Timing Data

This watch was the tightest-spec'd of the Module 75 series, but is currently performing far outside its 10 SPY factory spec., at about 45 SPY.

Day Deviation SPY Correction
0 -0.096 0  
20 3.046 57.3  
61 8.346 50.5  
88 10.962 45.8  
96 11.682 44.7  
105 12.4 43.4  
111 12.854 42.5  
117 13.254 41.6  
124 13.59 40.2  
130 13.828 39  
137 14.73 39.4  

Graph showing trends in deviation from Standard Time (in seconds) and rate (in seconds per year)


A Note on the Accuracy and Reliability of Timing Results

There is always going to be an unknown margin of error in any method of timing, and I estimate that each timing event could be off by as much as 0.1 second (though in practice I believe my results to be somewhat better than this). As a consequence of this potential margin of error, results over short periods of time are unreliable. Ultimately, the only result that matters is that which comes at the end of a full 365 days. Where interim results show consistent timings or steady trends, however, then it is safe to assume that those results are fairly accurate.