Can I see all dbus method calls on system bus?

I don't know really. But something still triggers those *_changed signals from com.nokia.time in accordance with my GUI actions, leading me to believe there's something else going on on the system bus I can't see.

Are you sure it's the system bus and not the session one?

@tortoisedoc About 90% sure.

i see following:

[nemo@Sailfish ~]$ dbus-monitor --system
signal sender=org.freedesktop.DBus -> dest=:1.143 serial=2 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameAcquired
   string ":1.143"
signal sender=:1.19 -> dest=(null destination) serial=3090 path=/com/nokia/time; interface=com.nokia.time; member=alarm_triggers_changed
   array [
      dict entry(
         uint32 251
         uint32 1464667200
      )
      dict entry(
         uint32 262
         uint32 1464666900
      )
   ]
signal sender=:1.19 -> dest=(null destination) serial=3091 path=/com/nokia/time; interface=com.nokia.time; member=next_bootup_event
   int32 1464666900
   int32 1466750700
signal sender=:1.19 -> dest=(null destination) serial=3092 path=/com/nokia/time; interface=com.nokia.time; member=alarm_triggers_changed
   array [
      dict entry(
         uint32 251
         uint32 1464667200
      )
      dict entry(
         uint32 262
         uint32 1464666900
      )
   ]
signal sender=:1.11 -> dest=(null destination) serial=110752 path=/net/connman/service/wifi_1ce19217006e_32474953_managed_ieee8021x; interface=net.connman.Service; member=PropertyChanged
   string "Strength"
   variant       byte 51
signal sender=:1.19 -> dest=(null destination) serial=3094 path=/com/nokia/time; interface=com.nokia.time; member=alarm_triggers_changed
   array [
      dict entry(
         uint32 251
         uint32 1464667200
      )
   ]
signal sender=:1.19 -> dest=(null destination) serial=3095 path=/com/nokia/time; interface=com.nokia.time; member=next_bootup_event
   int32 1464667200
   int32 1466750700
signal sender=:1.19 -> dest=(null destination) serial=3096 path=/com/nokia/time; interface=com.nokia.time; member=alarm_triggers_changed
   array [
      dict entry(
         uint32 251
         uint32 1464667200
      )
   ]
signal sender=:1.11 -> dest=(null destination) serial=110759 path=/net/connman/service/wifi_1ce19217006e_32474953_managed_ieee8021x; interface=net.connman.Service; member=PropertyChanged
   string "Strength"
   variant       byte 50

@coderus Well, yes, signals only. Something is still not right: I've opened two ssh sessions -- one to monitor system bus, one to poke around -- dbus-send --system --type=method_call --print-reply --dest=com.nokia.time /com/nokia/time com.nokia.time.get_wall_clock_info works fine, but it is never shown in monitor.