Ntpd won't save you from one particular rogue bit
<i>This means you can't actually persist the bad time to your RTC.</i><p>I wonder where that limit comes from, since the RTC in a standard PC stores both the year(00-99) and century(also 00-99) in BCD, so a date in 2153 should be representable.<p>This reminds me, one interesting thing I've noticed over the years is that early PC's RTCs were pretty accurate, but the most recent ones, as in the past few years, are horrible (as much as +/- several seconds per day), and the ones in smartphones even worse. Maybe because they're assuming NTP, so have cut costs by using less accurate crystals? I've had systems in storage for many years, and the RTC was within a few seconds of the current time when turned on again.