We distinguish two mechanisms by which effective dimensionality depends on timescale. Regime 1 (Measurement): An observer with bandwidth B and time τ can resolve∼2Bτ modes (Slepian-Landau-Pollak)—this applies to digital sampling and recordings. Regime 2 (Coupling): Biological oscillators continuously couple through physical interactions. A 1 Hz circadian oscillator encodes environmental dynamics at fine temporal resolution (bounded by coupling bandwidth and phase noise)—information is set by coupling bandwidth and SNR, not carrier frequency. Effective dimensionality depends on coupling propagation time and topology, not time-bandwidth products. For neural systems, the constraint is establishing phase coherence through anatomical connections (τcouple∼ms to s). For circadian rhythms, seasonal entrainment uses continuous coupling to photoperiod and temperature. Biological information processing exploits analog coupling consistent with channel capacity while exceeding discrete sampling constraints. We formalize both regimes and show most biological timescale-dependence reflects coupling dynamics. This explains why organisms achieve information densities appearing to violate sampling intuitions and connects to sub-Landauer limits where analog coupling operates near thermal noise. Our claims distinguish sampling-limited measurement from analog coupling, not contradict Shannon capacity. Keywords: expectation-biased stochastic resonance, working memory, magical number seven, predictive coding, neural oscillations, top-down control, top-down predictions, prefrontal cortex, structured noise, phase dynamics, analog coupling, timescales, consciousness, pareidolia, sub-Landauer limits