The 23 minute requirement is only for cellular standby mode.
If you are using any mode with cellular off the minimum recommended sleep time is 10 minutes, but the maximum is weeks, and that’s only because of the maximum length of the sleep time variable. You can wake up with cellular off, then immediately go back to sleep in under a second, postponing connection to cellular basically forever.
Thanks for quick response. Just to be sure I am correctly advising my customer, the following code is safe using 60 minutes check-in? All the possible scenarios in the Particle documents are a little confusing for a newcomer.
That’s the cellular standby case - the maximum sleep duration is 23 minutes from the last publish or keep-alive ping.
When using the mode, the time between wakes is nearly irrelevant in practice because the amount of power used by the cellular modem to maintain the cellular connection is so much larger than the amount of power it takes to wake the nRF52840 (assuming B Series SoM or Boron) to send a keep-alive that waking up every 23 minutes or every hour will have negligible effect on battery life.