An observation from my HR-V which (mis)behaves in a similar fashion to the Mk 3 Jazz.
I think, if the touchscreen system is paired with a phone via Bluetooth then it can grab the time / date from (or through) the phone. However, I found that my HR-V didn't change to DST automatically but, when I went into the settings, DST was off. So I enabled DST and then the displayed time was correct. I can't remember for sure what happened last October as I had only just got the vehicle. However, the HR-V was serviced only 10 days ago which was meant to include any software updates (the auto stop is now working enthusiastically) and an update might have reset DST to off.