bio

Range of entrainment

The band of day-lengths a given clock can be held to - and it is startlingly narrow, typically only a couple of hours either side of the clock's own natural period. The reason is mechanical: light can shift a clock only so far each day, so if the correction needed exceeds that budget, the clock does not slowly settle into step. It *lets go*, reverting to its own period and letting the world's day slide past. This is what makes a mismatched day a mechanical limit rather than a matter of adaptation: outside the band, no discipline and no adjustment period will do it.