Is it possible to sync Bangle.js 2 time to smartphone time?

I have also modified your bash example a bit, it runs on raspberry pi and uses the 0x2a0c "Exact Time 256"

advpad="00 00 00 00 00 00 00 00 00 00 00 00 00 00 00"

ble_advertise_datetime(){
  values="$(( $1&255 )) $(( $2/256 )) $3 $4 $5 $6 $7 $8 $(( $9/4000000 ))"
  sudo hcitool -i hci0 cmd 0x08 0x0008 10  02 01 06  0c 16 0c 2a $(printf '%02X %02X %02X %02X %02X %02X %02X %02X %02X' $values) $advpad
}

sudo hciconfig hci0 leadv 3
i=60
while [ $i -gt 0 ]  ; do
  echo $i
  ble_advertise_datetime  $(date "+%-Y %-Y %-m %-d %-H %-M %-S %-u %-N")
  sleep 0.5
  i=$((i-1))
done
sudo hciconfig hci0 noleadv