Best time and day to send cold emails: what the studies say

Weekdays beat weekends, and the middle of the week looks slightly best. Instantly's 2026 report puts peak replies on Tuesday and Wednesday, with Wednesday highest, and Backlinko's older study found Wednesday best and Saturday worst, by small margins. Time of day is less settled. Send in the recipient's working hours, in their time zone, and test your own list.

Every outbound team asks when to hit send. The internet is full of confident answers, a Tuesday at 10:00 here, a Thursday at 8:30 there. Most are repeated from one another. This post reads the two sources that publish data on it, says what they measured and how far to trust them, then turns the answer into a plan you can test.

What does the data say about the day?

Two things stand out. The sources agree on the shape: weekdays over weekends, midweek at the top. And Backlinko itself calls the differences between days "somewhat small". Wednesday is not magic. It is a few points better on an average that includes every kind of sender and audience.

Instantly's reason for Monday is also worth reading: Monday mornings are when prospects return with fresh inboxes and clearer priorities, so it suggests launching new sequences then. That is a reasoning, not a measurement, so treat it as a hypothesis to test.

What about the time of day?

Neither source gives an hour. Instantly names no specific time of day. Backlinko does not cover it. Anyone who gives you an exact minute for the best send is quoting a guess or a narrow sample.

What we can say is practical. A business reader opens email at the start of the day, after lunch and at the end of the day, and an email that arrives at 3:00 in the morning is buried by 9:00. So aim for arrival in the early part of the recipient's working day, and keep it consistent. Instantly also notes that erratic volume hurts deliverability, which is a reason to send at steady times and not in bursts.

Why does the time zone matter more than the hour?

Because a send time that is right for you is wrong for half your list. A message queued at 9:00 in Sofia arrives at 2:00 in the morning in Chicago. If your list covers several countries, sorting by time zone and sending in each recipient's morning beats picking one global best hour.

The Shelly installer programme reached installers in 111 countries. No single hour could be right for all of them, so the agent answered messages when they arrived, in a median of 1.4 minutes, with 70% inside 5 minutes. The first email's timing mattered less than being there when an installer wrote back. See the case study.

In Sellinger, send windows are set per connected account: you choose the days, a start and end time and a time zone. Without a schedule, nothing sends between 01:00 and 08:00 local time. The form starts at Monday to Friday, 09:00 to 18:00, and the default time zone is your browser's. The screen says hours are matched to the leads' working day, so check the first sends if lead local time matters to you. One more setting lets the agent answer replies on days off, which suits fast responses. See send windows and time zones.

Should you send follow ups on the same weekday?

Not necessarily. Instantly advises spacing touches three to four days apart. If your first email goes on Tuesday, the second lands on Friday or the next Monday. Friday afternoons are weak for most business readers, so if a gap lands there, move it. Keep gaps irregular enough that the sequence does not look like a machine, and keep them regular enough that you can predict your own volume. Our post on email sequences and cadences shows a full day by day plan.

Does the best day depend on who you write to?

Almost certainly. Surveys of senders give averages. Your audience has its own week:

• Shift workers and tradespeople may check email in the evening or on a Sunday.
• Executives may read in the first hour of the day or on a flight.
• Hotels, shops and restaurants have busy weekends and quiet midweek mornings.
• Public bodies and large companies work Monday to Friday, with slow Fridays.

The Hotel Pirin letters, written to HR and office managers, schools and event agencies, followed a calendar tied to the season: an autumn offsite from July, Christmas parties and January kick offs from late September. For that audience, the time of year mattered more than the weekday. See the case study, a related party study.

How do you find your own best time?

Run a simple test. It takes about three weeks.

1. Pick one segment with at least 600 people, in one time zone.
2. Split it at random into three groups of 200.
3. Send each group on a different weekday (for example Tuesday, Wednesday, Thursday) at the same local hour, with the same message.
4. Wait a full sequence, then count replies that say something real, not auto replies.
5. Compare. If the groups are within a point or two of each other, the day does not matter for you. Stop optimising it.

Small samples are noisy. Two hundred per group will show only large differences. That is fine: if the effect is small, you have better things to test, such as the list or the first line. Our post on A/B testing cold emails explains how many sends you need.

What about LinkedIn and other channels?

The two studies above are about email. For LinkedIn, the quiet window matters more than the weekday: on LinkedIn, the account's time zone is detected by default and the account sleeps from 1 AM to 8 AM, so nothing is sent in the middle of the night. Invitations and messages also follow daily limits, set per account, with defaults of 20 invitations a day and 150 a week. We have not found a study of the best weekday for LinkedIn that we trust, so apply the same test as above to your own audience. For WhatsApp, the platform limits outbound messages, so send times matter less than who you pick.

One thing holds across channels: a fast reply beats a perfect send time. Once someone answers, the clock starts, and the agent should respond in minutes at any hour. That is why the setting to let the agent answer replies on days off exists.

A practical plan

• Send Monday to Friday. Skip weekends for business audiences.
• Start with Tuesday and Wednesday for first touches, and keep Monday for launches you want to test.
• Send inside the recipient's working day, in their time zone.
• Keep volume steady from day to day.
• Move follow ups off Friday afternoons.
• Test once on your own list, then stop.