Definition
Email date testing is the practice of systematically testing which days of the week (and times of day) your emails perform best for your specific audience. Rather than copying generic "best time to send" advice, date testing uses your own data to find the timing that drives the strongest opens, clicks and conversions.
It differs from send-time optimisation, which personalises timing per recipient with models; date testing typically compares timing across test groups or campaigns.
Common Date Test Approaches
| Approach | How It Works |
|---|---|
| Split send groups | Different segments receive the same email at different dates or times |
| Rotating schedule | Rotate send days across campaigns and compare results |
| A/B timing test | Test a time against another on similar audiences |
| Cohort benchmarking | Compare results for the same date across periods |
The goal is to isolate timing from other variables so you can see the effect of the date and time alone.
Factors That Affect Send Date Performance
- Audience habits: When your subscribers typically check email.
- Timezone and geography: Whats makes sense in one region differs elsewhere.
- Content type: Time-sensitive vs evergreen content responds to timing differently.
- Business calendar: Launch dates, paydays and seasonality all shift the ideal date.
- Competitive noise: When aggressive competitors are sending.
How to Run a Date Test Well
- Test one variable at a time: Change the date only, keeping content identical.
- Use a large enough sample: Ensure each date group reaches statistical meaning.
- Segment carefully: Keep audiences similar so timing, not audience, drives differences.
- Track business outcomes: Prefer conversions and revenue over opens alone.
- Review over time: A single test is only a snapshot; timing shifts as habits change.
Related Glossary Terms
Account-Based Marketing Email
An account-based marketing email is a highly targeted message sent to a specific organisation or decision-maker group as part of a focused B2B strategy.
Announcement Email
An announcement email is a dedicated campaign that communicates a specific update, milestone, or change to subscribers, from product launches and feature releases to company news and events.
B2B Email Marketing
B2B email marketing targets business professionals and organisations with longer sales cycles, educational content, and relationship-driven campaigns compared to B2C email.
B2C Email Marketing
B2C email marketing focuses on sending targeted promotional and transactional emails to individual consumers, emphasising personalisation, urgency, and direct response.
Behavioral Email
Behavioral email is a message triggered by a subscriber's action, inaction, or engagement pattern, making it more relevant than scheduled broadcast sends.
Behavioral Segmentation
Behavioral segmentation is the practice of grouping subscribers based on their actions, such as opens, clicks, purchases, browsing and engagement patterns.
Frequently Asked Questions
Email date testing is testing which send days and times engage your audience best, using your own data rather than generic advice. You compare results for different dates or times to find the strongest timing for your list.
Send the same email on different days to similar test groups, hold other factors constant, and compare opens, clicks and conversions. Use a large enough sample and run the test for long enough to trust the result.
There is no single best day. What performs best depends on your audience's habits, geography, type of content and business calendar. Date testing with your own audience produces a far more reliable answer than a general benchmark.
Yes. Send-time optimisation typically predicts and personalises the optimal time per recipient using models. Date testing compares timing across groups or campaigns to find the best schedule for your audience overall.