The town I go to school in has a highly antiquated electrical system. The wires feeding streetlights (120/240v; many are glass lensed NEMA buckets of 100&175w MV!) are highly degraded with mostly bare lines, which has wispy fibers dangling from it, so I assume it is asbestos insulated wire. The new sections of wire has black rubber insulation that isn't degraded very much. I notice that the lights will sometimes dim for a fraction of a second and then everything is all good. I talked to the teachers and they said that its from them working on the school (they're adding on a new part of the south wing in addition to the demolition and rebuilding of most of the main building in the summer). A few times around 2:00pm, the power has gone completely out for about a min to the whole place. My computer teecher said that a gust of wind is enough to make the lights dim in the whole town of about 800 peeps lol.
That reminds me of when I was at TAFE (college) a number of years ago. Lightning struck a power pole outside and knocked out power for a few minutes. When it returned, the computers would power on like normal but the connection to the server didn't work. Apparently the network hub was fried.

What I don't understand is the label 'real time clock fitted'. Why would it need a time clock when this unit replaced an older style time clock? I thought the idea of these ripple control units was to enable the electricity supplier to have complete control of the switching cycles? For the ripple control receiver to also have a time clock as well, doesn't make sense to me. Looking at the unit, a time clock is not obvious.
That is strange indeed. I know these modern units are programmable using an IR link by the engineer so perhaps the clock is programmed in but like you say it's pointless to have a time clock built in if it's a ripple switch.