In the timer settings, if you choose NTP as the time source, it will update every 30 minutes (default setting), so your clock should be set correctly at that point. Alternatively, you could use DVB time to set the internal clock. A log would be useful. At boot time the default used to be 1/1/1970, but since the introduction of the fake hw-clock some years ago, the default date/time at boot is set to be the last shutdown time. This may be messing with CrossEPG timer.