I am not sure how the GX sets the time of day during the period of Daylight Saving Time. There does not seem to be an option in the menu, UTC (or GMT) is the only relevant option which is of course 1 hour out in the UK until 31st Oct when DST ends. This would not be a problem where it not for the fact that some energy suppliers time their low rates at the same time irrespective of whether it is DST or not which means changing the battery charging start time.