SystemClock breaks across Daylight Saving Time transitions

[just-some-entity]

When the Daylight Saving Time transitioned today, the scheduling of the SystemClock breaks and the interval computed in SystemClock::schedule (this->timer.start(static_cast(delay)) to be precise) becomes a negative number, printing the warning "WARN: QTimer::start: negative intervals aren't allowed; the interval will be set to 1ms." every time the timer is started, flooding the console output.