Fair Warning: This Post Is Inconsequential
As I was going through the process of changing clocks and watches for today's presto-chango of daylight hours, I worked my way down to my everyday watch. My good old (and I do mean old) reliable Timex Ironman Triathlon has been set at three minutes fast since my memory runneth not to the contrary. I don't even think I set it that way intentionally. It just sort of evolved. But I always knew that it was three minutes fast so when I referred to it for the time, I knocked off those three minutes.
Now, the watch is set to second per my Mac which gets its time set automatically from Apple's time server. Pretty reliable I do believe. So the remaining question is whether I will now keep in mind that my watch is not three minutes fast. I go with "probably."