Emoncms will just log whatever an EmonESP device sends, the timezone is not critical, it is just used for timer control functionality as far as I can remember.
E1 & E2 are set on the EmonTx and depending on the firmware version you have, it will either reset on a power cycle or be saved to EEPROM. What behaviour are you seeing?
The emonTx has no concept of time of day, week, month or year. The only time it knows is between sending blocks of data by radio or via the serial port.
If you look in the documentation for emonLibCM, the details are there (EmonLibCM_getWattHour).
Hello @ishtangli what does your emoncms input processing look like for the cumulative kWh feed?
Are your using ‘Log to feed’ and ‘Power to kWh’? Or on the E1 and E2 inputs you need to use ‘Log to Feed (Join)’ otherwise you can get gaps in the cumulative kWh data that cause the graphs to miss days, which may be what you are seeing - or it may be a completely different issue