48 minlater wake-up by the clock on the first morning after the clocks spring forward. Body clocks take days to follow.
Babies follow their internal clock, not the one on the wall. On the first morning after the change European babies woke 50.3 minutes later by the clock in 2025 and 48.4 minutes later in 2026, and a week later wake-up was still around 22 minutes later than before. Bedtime moved less, by about 19 minutes on the first evening, and in autumn the pattern reverses with wake-up about 36 minutes earlier.
Complete days rebuilt from parents' own logs (a day counts when a parent logged the wake-up, every nap and bedtime), local wall-clock time, babies aged 3 to 18 months; no settled-routine filter. For each baby, wake-up and bedtime on each day from the change day to 14 days after, minus that baby's own average over the 7 days before the change (at least 4 of them), averaged across babies. Europe = EU/EEA countries plus the UK, Norway and Switzerland, by where the app is used. EU spring 2025 (30 Mar): wake-up +50.3 min, bedtime +19.2 min, 59,689 babies. EU spring 2026 (29 Mar): wake-up +48.4 min, bedtime +18.9 min, 92,913 babies; still +22.0 min on day 7 and +12.8 min on day 11. EU autumn 2025 (26 Oct): wake-up -35.9 min, bedtime -17.9 min, 67,014 babies. US spring 2025 and 2026: +46.4 and +42.2 min (2,527 and 3,328 babies); US autumn 2025: -33.6 min (2,588 babies). No comparison year without a clock change is available, so part of the leftover shift after two weeks may be ordinary seasonal drift.