The best time to ask for Amazon book reviews is after the reader has had enough time to finish the book. Asking too early feels pushy. Asking too late loses momentum.
For most authors, the clean window is launch week plus one follow-up.
Before Launch
Give ARC readers enough time to read. Do not send the book two days before launch and expect thoughtful reviews.
Two to four weeks is often more realistic for a short book. Longer books may need more time.
During Launch Week
Send a short reminder when the Amazon page is live. Keep it neutral: if they read the book, an honest review would help other readers.
Do not ask everyone to post at the exact same hour.
After Launch
Send one gentle follow-up later. Then stop.
Review requests work best when they feel like a reader invitation, not a campaign command.