There is no universal best time to send. The list-wide answer is whenever the bulk of your audience tends to read, which you find from your own data. The real lift comes from per-recipient send-time optimisation: each contact gets the email at the moment they usually open.
Why one best time is the wrong answer
People open email at different times depending on job, lifestyle and time zone. A list-wide best time is just the average of all those patterns, which is no one's actual best time. See the glossary entry on send-time optimisation for the short definition.
How per-recipient timing works
The system learns each contact's open pattern from history, predicts the next opening window, and queues the send for that moment within a campaign window you set (for example, sometime today between 7am and 9pm local).
When list-wide timing is fine
- Time-bound offers (a sale that ends at midnight).
- Newsletters with a strict publication slot.
- Lists too small or too new for a per-recipient model.
Time zones and global lists
Even without per-recipient optimisation, sending in local time zones beats sending in your time zone. Most ESPs support this; turn it on.
Frequently asked questions
Will per-recipient timing slow down the campaign?
It spreads the send across the window you set, which is usually a good thing for reputation. It does not change total send volume.
Does send-time matter more than subject line?
Usually no. Subject and from name move opens more. But timing is free lift on top of those.
Should I send on weekends?
Depends entirely on the audience. Test it for your own list rather than following generic advice.