4:00 a.m.starts the busiest half-hour for parent-recorded night wakings between 11 p.m. and 5 a.m. Wakings build as the night goes on.
Wakings are rarest in the first part of the night and climb steadily towards early morning, when sleep is naturally lighter. The half-hour from 4:00 to 4:30 am holds 7.2% of all parent-recorded evening and night wakings, roughly twice the share of 11:00 to 11:30 pm.
Raw NIGHT_WAKING logs of 10 to 90 minutes (autotrack logs excluded), start time converted to local wall-clock time with each log's timezone offset, babies aged 0 to 18 months, logs from Sep 2025 to Aug 2026. Wakings starting 19:00 to 06:59 are placed in 30-minute buckets. Each baby with at least 5 such wakings gets one vote: we take the share of that baby's wakings in each bucket and average the shares across babies. 367,785 babies, 29.1 million wakings (18.7 million between 23:00 and 05:00). Within 23:00 to 05:00 the top bucket is 04:00 to 04:29 (7.23%), followed by 03:00 to 03:29 (6.43%); 05:00 to 05:29 is almost as high (7.12%) but falls outside the window and may include early wake-ups logged as wakings. Parents often round logged times to the hour or half-hour.