Can someone tell me how the total hours of operation can be displayed on DSOX MSOX 3000A Series Oscilloscopes?

Can someone tell me how the total hours of operation can be displayed on DSOX MSOX 3000A Series Oscilloscopes?

- Are you sure of this? The 3000 X-Series User's Guide states; "Perform user- calibration: ...after 4000 hours of operation". Is one supposed to just guess at this number? Competitive scopes can display total hours of operation, could this important and informative function be something overlooked on the 3000X?

Bob