Short answer: there isn't one best hour. Most advice says "within an hour", and most tools default to it — but that's a convention, not a finding about your customers. The useful question is when your shoppers are usually active, and that differs from store to store. Here's why, and how to find your own window.
Merchants spend hours polishing subject lines, testing discounts, and rewriting calls to action. Then they send every cart-recovery email exactly one hour after abandonment — because that is the default.
But a fixed one-hour delay optimizes for elapsed time, not for the shopper's next receptive moment.
Every audience has a buying rhythm
Different stores attract shoppers at different times.
A baby-gear store may find that many parents browse after bedtime. A B2B parts supplier may see most activity during working hours. A snowboard shop might peak on weekend mornings.
A reminder sent outside those windows has to compete with everything else in the shopper's inbox. One sent during a naturally active period is more likely to arrive when returning to the purchase feels relevant.
The right window will not be the same for every store — or every shopper.
Fixed delays ignore context
Rules such as "send after one hour, then again after 24 hours" treat every abandonment identically.
Someone who leaves a cart at midnight receives the same delay as someone shopping during a lunch break. A campaign scheduled in the store's timezone may also reach international shoppers late at night.
Fixed delays are simple, but they cannot adapt to your audience's actual behavior.
How Cartback chooses a send window
Cartback first analyzes your catalog to estimate an initial audience profile, such as evening shoppers, business-hours buyers, or weekend browsers.
Its scheduling system then combines that starting profile with additional signals:
- your store's audience timezone (configurable), while avoiding typical overnight hours;
- the hour at which the shopper was last active on your store; and
- the send hours that have historically recovered carts for your store.
As more recovery data becomes available, Cartback refines the recommended windows. This is store- and audience-level optimization — no per-shopper profiling. Merchants can also lock a profile or define a custom send window when they already know their audience well.
Check your store's buying rhythm
Open your Shopify order list and look at the local hour of your last 50 to 100 orders. Do the orders cluster around particular parts of the day or week?
This does not prove the ideal time for a cart reminder, but it can reveal a pattern worth testing. Compare that pattern with your current recovery schedule — you may find that many reminders are being sent when your customers are rarely in buying mode.