I have this issue with the 'gas' metric of the P1 Smart Meter.
The Domoticz logs say that the clock is ahead (notice that it's a negative value)

When I check minicom, it does actually provide the gas data:

In the highlighted line, the format appears to be: YYMMDDHHmmss[literal "S"]
My theory is that, the timestamp adds an 'S' for 'Savings' or 'Summer' and this messes up the interpreter within the P1 Smart Meter USB module.
Also, I know that the gas meter DID work during the winter. (So when there was no DST-- Daylights Savings, a.k.a. Winter Time)
I tested this on my own Smart Meter and my friend's, both on Domoticz Stable and on Domoticz Beta. Same results.
Is there anything I can do, or is this a bug?