How do I test the best time to send emails?

Send time testing requires systematic experimentation across time windows:

Define test windows: Morning vs afternoon vs evening. Weekday vs weekend. Specific hour slots if you want precision.

Split your audience randomly into groups that receive identical content at different times. Random assignment prevents segment bias.

Measure primary metrics: Open rate is most affected by send time since timing determines when recipients encounter your message.

Measure secondary metrics: Click rate and conversion rate to ensure opens translate to action.

Run for multiple weeks to account for week-to-week variation and ensure statistical significance.

Segment analysis: Optimal times often vary by audience segment. Business recipients behave differently than consumers.

Send time optimization finds when your audience is receptive. The best content sent at the wrong time underperforms.