School-entry cut-off dates may incentivize parents to delay or hasten births due near the cut-off. Research has documented this behaviour in Asian countries, where educational competitiveness tends to be intense. Using an extensive database extracted from administrative registers, we found no evidence of this behaviour in Spain. Our results hold even when stratifying the sample by mother’s educational attainment and country of birth. These findings not only confirm the distinction between European and Asian contexts; they also serve as a robust empirical ground for those works that assume randomness in births around the school-entry cut-off in regression discontinuity designs.