Timing storytime to maximize children’s ability to retain new vocabulary

•Caregivers read children (aged 5–7 years) a story containing novel words.•New word production and comprehension were better at the 24 hr than 0 hr test.•Children with better vocabulary showed larger overnight gains in comprehension.•Overnight comprehension gains were largest if the story was read 3–5 hrs before bed.•Findings lend ecological validity to lab-based findings in word learning.