@imaddicted2u Following your description and the clue you provided, the device timer was not aligned with the server’s timestamp in a specific time zone. As you can see from what I’ve reported before, this issue can not be reproduced in our local time zone. Currently, we reproduced the problem by setting the same time zone as yours to see what would happen.
We also received your ticket in our support system, if there is any progress, we will update you via the ticket.
Thank you so much @Daniel_Zhan Daniel. I really do appreciate your efforts in getting to the bottom of the longstanding History data issue. Not much point looking at yearly history graph or downloading history csv data that is incorrect.
It looks to me that the test environment you showed is looking at current month data, when it is History graph data that gets corrupted because the History data stored on the server gets corrupted.
The only thing you will see by looking at the daily graph is the impact of the difference between Atlantic standard time and Atlantic standard time, at the end of the month, for 1 hour, when the month changes.
Looking at the monthly data graph, at change of month, it looks like the data has disappeared but it hasn’t, the data displayed in the eWeLink app is confused by the time difference caused by daylight time.
Having multiple issues may be confusing things.
On the issue with downloading 4 history csv files, from 4 different devices, one after the other, being longer than the previous csv file, I fail to see how time zone could impact or cause that. Note all 4 files are for the same date range, so all should stop at line 194.
In my ticket to SONOFF, I included all the files that show what happens when the corruption happens and 0’s are inserted and displace the correct numbers and ho the 4 csv files are different lengths.
The S40 devices work well as smart plugs and instantaneous power consumption monitors, making the historical data collection and storage work properly will make them perfect.
Thanks for your info and patience for such an issue, we have escalated this issue to our engineering team as we also found some abnormal data in the device log. Our team was involved in analyzing the case according to all the information that you provided. I hope we can fix the issue ASAP.
Thanks again @Daniel_Zhan. I appreciate the efforts of everyone involved on the team.
@Daniel_Zhan feels like progress, I was asked to share my devices so the issues could be investigated further… 
Just received firmware update…Ver 1.41 to 1.42.
Yes, we fixed the issue and bugs of the firmware, please observe whether the problem has been resolved.
Thanks for your patience. 
I really appreciate the dilligence of the SONOFF team on these issues.
I will check the results on the yearly history graph, over time, for errors.
So far, I can confirm that the History csv files are still different lengths. Aron said the app team are still working on the csv file problem.
The Today run time total is still -1 hour compared to the local time. Aron said I could try to delete and reinstall the devices but to wait until the app team is finished with their review so the device sharing is not lost.
Good news, all downloaded CSV files are the same length since the app was updated to 5.7.0
Thanks to everyone who helped resolve all the issues I faced.
