This page simulates the HES1-HES5 hybrid oscillator model from Biga et al. (2026, Development 153, dev204969). HES1 and HES5 are co-expressed in cortical neural progenitor cells and form a coupled delay-differential equation (DDE) system where each protein auto-represses itself and cross-represses the other. Three dynamical regimes are simulated: balanced co-expression (both proteins oscillate, period ~6.4 h), HES1-dominant (HES5 suppressed, HES1 free-running period ~2.55 h), and HES5-dominant (HES1 suppressed, HES5 free-running period ~3.3 h). AR(2) is fitted to each timeseries. All three regimes produce |λ| ≈ 0.999 with complex roots — consistent with near-sustained limit cycle oscillations. The coupled period (~6.4 h) is longer than either free-running period, a prediction of coupled oscillator theory. This page is the first AR(2) characterisation of HES1/HES5 dynamics and extends the PAR(2) framework from circadian biology into developmental neuroscience.