The former librarian Susan M.'s blog From Tots to Teens recently posted a wonderful review of Broom, Zoom! in which she points out, among other things, that while this book is about a witch and a monster and the moon, it is definitely not a Halloween book. They do not reference the holiday at all, making it a wonderful book for sharing and reading at any time during the year.
P.S.: only one note: while it is true that the color was done digitally, the line was my usual good old pen & ink on paper!