GN: Unix Timestamp Synchronization

I’d like to update the timestamp on the Generic Node (GN). The goal is for the gateway to send a Unix timestamp to the GN, which would then store it in non-volatile memory.

However, updating the GN’s local time isn’t straightforward. The system time (SysTime_t) is represented as a struct with two fields: Seconds and SubSeconds. While I could use the SysTimeSet() function from the Utilities module, it doesn’t seem to be designed specifically for setting a Unix timestamp.

Is there a built-in function in the lower layers of LoRaWAN that handles Unix timestamps directly? I’m aware that ADR is implemented, but not sure about time synchronization.