A Second Is A Hiccup, by Hazel Hutchins, explains the concept of time to young children with analogies that they can easily understand. A question begins each section (e.g. “How long is a week?”) for a second, a minute, an hour, a day, a week, a month, and a year. I found that the book loses its rhythm after explaining how long a second and minute were, making this book difficult to read aloud on a cold run.
This is a good book to have on hand if asked “how long is a week?” Otherwise, I would stick to just reading the first few pages, which hold together much better than the loose structure of the rest. Watercolor illustrations are nice and show diverse families (diverse in age and ethnicity), all playing together as well as separately in their own homes.