There isn't a single best time to send marketing emails. There is a best time for each subscriber on your list.
Across our data, Tuesday at 10 AM (the conventional wisdom) is one of the worst times to send — because every other marketer is also sending then. Your email lands in a crowded inbox at peak triage.
The marketers who win in 2026 are not picking a day or a time. They are picking per person, automatically, based on each individual's engagement history.
- Why "when is the best time to send" is the wrong question
- What aggregate data actually says (the 2026 numbers)
- The "Tuesday at 10 AM" myth and why it stopped working
- B2B vs B2C: where the conventional wisdom diverges
- The per-person send-time approach (and why it lifts opens 20–60%)
- How to implement send-time optimization in HubSpot or Marketo
- Frequently asked questions
Why "when is the best time to send" is the wrong question
For two decades, email marketers have hunted for the magic send time. Tuesday at 10 AM. Thursday at 2 PM. Sunday evening for retail. The hunt has spawned hundreds of blog posts, infographics, and "best time to send email" calculators.
The hunt is a category error.
Your audience is not a single entity. It is thousands or millions of individuals with different jobs, time zones, devices, sleep patterns, and inbox habits. Asking when is the best time to send email is like asking what is the best temperature for a restaurant. The answer depends on who walks in.
The right question is: when is the best time to send this email to this person? That question has 100,000 different answers if your list has 100,000 people. And the only way to answer it is at the individual level, with data.
What the aggregate data actually says
We analyzed 700+ million marketing emails sent through HubSpot and Marketo by Seventh Sense customers between January 2024 and May 2026. Here is what aggregate timing looks like across the full dataset:
| Day of week | Median open rate | Median click rate | Median unsubscribe rate |
|---|---|---|---|
| Tuesday | 22.4% | 2.9% | 0.18% |
| Thursday | 22.1% | 2.8% | 0.17% |
| Wednesday | 21.6% | 2.7% | 0.18% |
| Monday | 20.8% | 2.5% | 0.21% |
| Friday | 19.9% | 2.4% | 0.19% |
| Sunday | 18.2% | 2.2% | 0.15% |
| Saturday | 17.4% | 2.0% | 0.14% |
Tuesday wins. Saturday loses. The conventional wisdom is correct — and almost meaningless.
The spread between the best day (Tuesday) and the worst day (Saturday) is only 5 percentage points. When we ran the same analysis at the per-individual level, the spread between each subscriber's best time and their worst time was 14 to 38 percentage points.
In other words: picking the right day picks up 5 points of open rate. Picking the right time for the right person picks up 14–38 points. The day-of-week conversation is a rounding error compared to the person-level conversation.
The "Tuesday at 10 AM" myth and why it stopped working
Every marketer reading this article knows the rule: send Tuesday at 10 AM Eastern. It has been the default for a decade. It is also why it stopped working.
Tuesday 10 AM Eastern has become the most crowded send window in marketing email. Every B2B SaaS company, every newsletter, every nurture campaign fires within a 30-minute window from 9:45 to 10:15 AM ET. The result, in inbox terms, is a traffic jam.
Gmail's Promotions tab does not score emails individually — it scores them in the context of what else arrived at the same time. When you arrive in a flood, you compete for attention with hundreds of other senders. When you arrive at 6:47 AM (because that's when your subscriber checks email), you are one of three.
An A/B test we ran across 12 customers found that the same email, sent to the same audience, posted a 28% higher open rate at the recipient's individual peak hour than at the campaign's "optimal" 10 AM Tuesday send. Same content. Same list. The difference was timing relative to crowding.
B2B vs B2C: where the rules actually diverge
One thing the conventional wisdom gets right: B2B and B2C have meaningfully different timing patterns. Here is what the data shows.
B2B
- Best window: 8 AM – 11 AM local time, Tuesday–Thursday
- Sharp drop-off after 6 PM local: opens fall 40–60% outside work hours
- Weekends underperform: Saturday/Sunday open rates drop 30–60% vs. weekday peak
- Monday morning is a trap: high volume but subscribers triage inbox quickly; click rates are 15–20% lower than Tuesday
B2C
- Best windows: 6 AM – 9 AM (morning commute) and 7 PM – 10 PM (evening)
- Weekends perform well: Sunday evening is the single highest-engagement window for retail and ecommerce
- Mobile-first: 78% of B2C opens happen on a phone; send-time matters more than ever
- Time zone scatter: if your list is national, sending in ET means 23% of opens never happen because your PT subscribers are still asleep
None of this matters at the individual level. Your accountant subscriber in Phoenix who only checks email at 6:14 AM does not care that the B2B average is 9 AM. She is going to open your email at 6:14 AM or not at all.
The per-person send-time approach
Per-person send-time optimization (PPSTO) is the practice of scheduling each individual email send for when that specific recipient is most likely to engage, based on their historical email behavior.
It is not new. Amazon, Netflix, and big-tech notification systems have done this since 2016. What is new is that it is now available to mid-market marketing teams natively inside HubSpot and Marketo — no engineering required.
Here is how it works in concrete terms:
- Build a per-person profile. For each contact, log every open, click, and inbox interaction across email and time-of-day. After 30–60 days, you have a probability distribution: this person opens email between 7:14 AM and 8:02 AM with 73% probability on weekdays, and almost never on weekends.
- Predict the next-best send time. Given the profile, the model predicts the highest-probability window for this person in the next 24–48 hours. The window is usually 30–45 minutes wide.
- Schedule the send for that window. Instead of "send to segment at 10 AM Tuesday," the platform sends 100,000 individualized sends across a 24-hour window — each one timed to its recipient's peak.
- Update continuously. Habits drift (job changes, time zone changes, kids, vacations). The model re-trains daily on the most recent engagement signal.
"Despite sending 44% fewer emails year-over-year, we grew our email marketing revenue by 11%. Our open and click rates doubled." — Greg Moore, ProAthlete Inc, HubSpot customer
Want to see your data?
Plug Seventh Sense into your HubSpot or Marketo portal. The AI surfaces each contact's optimal send window within 24 hours — no code, no setup, no credit card.
Try it free →How to implement send-time optimization in HubSpot or Marketo
There are three honest paths to per-person send-time optimization. They are not equally good.
Option 1: Build it yourself with HubSpot or Marketo native features
Neither platform offers true per-person send time. HubSpot has a "send time optimization" feature that picks the best day for your list, not for individuals. Marketo's optimal-send-time is similar. Both are list-level heuristics dressed up as AI.
You can approximate per-person scheduling by manually segmenting your list into time-zone buckets and creating separate send waves. This works at small scale and falls apart above 20,000 contacts because the segmentation overhead exceeds the lift.
Option 2: Use a dedicated send-time AI
Tools like Seventh Sense run a model per contact, predict the optimal window, and execute the send natively inside HubSpot Workflows or Marketo Programs. Setup takes 12 minutes. Results show in the first send.
This is the option 1,000+ marketing teams currently use, including Marketo customers who specifically chose us over Adobe's native optimal-send-time feature.
Option 3: Engineer your own model
If you have a data engineering team, the data to do this yourself is available via the HubSpot Email Events API and Marketo's Bulk Lead Extract API. The hard part is not the model — it's the operational layer (queuing, throttling, deliverability monitoring, reputation management) that keeps the sends from breaking your domain. Most teams build this once, then abandon it.