Activity + Sleep = 18:36?

[0000162543]

Hi all, 

I pull data from API and do some analysis on google sheets. I noticed the following and want your feedback. 

I used to get 24:00 when summing activity (sedentary minutes + lightly active minutes + fairly active minutes + very active minutes) and sleep (4 stages). But I have been getting 18:36 (activity + sleep) since the beginning of the year. I noticed shorter sedentary minutes since the same day.

I have following questions:
- why 18:36? 
- what does my device think I'm doing when I'm not sitting and engaging in light activities? 
- where is 5.5 hours of my data?

[GordonFitbit]

Hi @0000162543 

I don't know if I would recommend adding up the activity and sleep data to see if 24 hours of data appears.   But, if you have been doing this and it has been working for you, then great!   I suppose the discrepancy could be generated by off-wrist time where the user has taken off the device or doesn't have a good connection.   Have you tried looking at the detailed data to see if the missing data points is coming from the activity or sleep logs?