This reminds me of a story one of my college professors told about the days when he helped automate factories in the 80s. Every night, the control server hey installed would go offline around 1am then come back up a few minutes later. It was never the exact same time or duration. After a few days of diving through the code with no progress, one of his co-workers decided to stay up all night at the factory and just watch the server. Around 1am, the cleaning lady came in, unplugged the server and plugged in her vacuum.