"Tuesday at 10am" gets repeated so often as the universal best time to send email that it's become received wisdom nobody questions. It's also based on aggregate data across industries and audiences so different from each other that the average is nearly meaningless for any specific business trying to apply it.
Here's a more honest look at what actually determines the best time to send, and how to find your own answer instead of borrowing someone else's.
Why the generic answer doesn't transfer to your business
"Best time" studies typically aggregate email opens across thousands of businesses — SaaS companies, retail brands, newsletters, nonprofits, all mixed together. The resulting average tells you what time email tends to get opened in general, which is a completely different question from what time your specific list opens email.
A B2B audience checking email during work hours behaves nothing like a consumer audience checking email in the evening after work, or a global audience spread across time zones where "10am" means something different for each subscriber. The generic advice isn't wrong, exactly — it's just answering a question that isn't yours.
The real factors that actually determine timing
What your audience does for a living, and when. A list of accountants checking email between client meetings behaves differently from a list of freelance creatives who might check email at 11pm because their schedule doesn't follow a 9-to-5 rhythm at all.
What device they're likely reading on. Mobile-heavy audiences tend to check email in scattered small windows throughout the day — commute, lunch break, before bed. Desktop-heavy audiences (common in B2B) tend to cluster more tightly around work hours.
What you're actually asking them to do. An email that requires ten minutes of focused reading needs a different moment than an email that just needs a quick click. Sending a long-form piece at 5pm on a Friday, when people are mentally checking out for the weekend, sets it up to fail regardless of how good the content is.
Time zone spread. If your list spans multiple time zones, "the best time" isn't a single moment at all — it's either a compromise time that's imperfect for everyone, or it requires actually splitting sends by time zone, which most small email tools can do more easily than people assume.
How to actually find your best time, using your own data
Step 1: Look at what you already have. If you've sent even a handful of emails, look at your own open-rate data by day and time already. Most email tools show this per campaign — the pattern in your own past sends is worth more than any external study, because it's about your actual audience.
Step 2: Test one variable at a time. Pick two candidate times (say, 9am and 7pm) and alternate between them for your next several sends. Don't change the content style or frequency simultaneously — you want to isolate timing as the one variable that changed.
Step 3: Give it enough sends to be meaningful. Don't draw conclusions from one email at each time. Four to six sends per time slot gives you a much more reliable pattern than a single data point that could easily be noise (an unrelated event, a holiday, a coincidence).
Step 4: Segment the test if your list is diverse. If you have distinctly different audience segments (say, one segment of business owners and another of hobbyists), consider that they may have genuinely different optimal times — testing them as one combined group can wash out a real pattern that exists within each segment separately.
What to do if you genuinely don't have enough data yet
If you're just starting and don't have send history to analyze, a reasonable starting assumption for most B2B audiences is a weekday, mid-morning send (roughly 9–11am in the recipient's likely time zone) — not because it's guaranteed optimal, but because it avoids the clearest bad choices (very early morning, late evening, weekends) while you build up enough of your own data to actually test properly.
For consumer-facing audiences, evenings and weekends are often underrated — many businesses default to weekday mornings out of habit, inadvertently competing with everyone else's email in the same crowded window, when a quieter evening slot might actually get more attention specifically because fewer other businesses are sending then.
The takeaway
There's no universal best time to send email — there's a best time for your specific audience, discoverable only through your own data, not someone else's aggregate study. Start with a reasonable default if you have no data yet, then test deliberately, one variable at a time, with enough sends to see a real pattern instead of noise. The answer that works for your business will very likely differ from the generic advice — and that's exactly why finding your own answer is worth the effort.