Date and Time in LPWA modules

Is there any Power Saving mode which makes the Quectel module lose current time and date? Or current date and time obtained from the visited network is maintained by the communication module as long as it’s powered by the device?

What network do you need the module to work on? NB - IOT or CATM?


Related to this topic, I’ve observed weird behavior related to the date communicated by device to my SIM.
With BG95, time reference (6st January 80) is still being sent in the Provide Location Info response, while I can observe (via AT+CCLK) that proper date has been fetched from the network after attach.

Is this the expected behavior? May we ideally have also the proper date communicated via STK interface?

On the other hand, with a EC21 model, it looks to work as expected: it starts obviously with same reference (6st January 80) but afterwards it’s able to tell the SIM about proper date, once registered.


Hi Herbert, both actually.

You can choose more Quectel LPWA modules, such as BG95 BG96 / BG77 BG951 / BG770A, etc.; After the module successfully registers the network, it can obtain the time and date

Thanks a lot Herbert. The question is: after power cycle, before new successful attach, will these modules remember previous time and date? Or will they go back to 1980?

The default initial time (1970-1-1) will be displayed before the module initially registers the network. After registering THE NETWORK successfully for the first time, the module will get the clock source from the network and then carry it through the crystal. There will be no problem of the time returning to the default value

Thanks Herbert. However, my real observations are quite different to what you explained:

  • After network registration indeed device learns the proper Date, BUT the one communicated to the SIM is still with the old reference (6/1/80).
  • Rebooting the device turns back the time reference to 6/1/80.

Could you please double check?

What modules are you using? And upload your relevant log

BG95M3 is facing this behavior, while in EC21 the proper date/time is exchanged.

I attach a case after rebooting my BG95 device (AT+CCLK returning proper date): (5.9 KB)

  • Message 152: Normal service Envelope.
  • Message 154: Provide Location Info Response from device with 6/1/80 00:00:11