Daylight Saving Just Happened. Here Is What It Does to Your Email Open Rates.
Daylight saving time shifts open-rate windows across time zones. Here is how to adjust your send schedule, run a timezone A/B test, and protect your email performance for the next few weeks.
Clocks moved forward yesterday. That one-hour shift changes when your subscribers actually open emails, especially for morning and evening send windows. Open rates tend to dip in the first week after DST as people adjust their routines, then normalize by week two. The tactical fix is simple: shift send times 30 to 60 minutes later, segment your list by time zone if your platform supports it, and run a quick A/B test to revalidate your best send time before April.
Clocks moved forward yesterday morning.
For most people, that means losing an hour of sleep and spending a week feeling slightly off. For email marketers, it means the open-rate patterns you have spent months learning are temporarily off by an hour.
This is not a crisis. It is a two-week calibration window. Here is what to watch and what to adjust.
What Daylight Saving Does to Email Behavior
Email open rates are not random. They follow behavioral patterns tied to daily routines: morning commutes, lunch breaks, post-work wind-down, pre-sleep phone checks. When you have been sending at 8 a.m. and consistently seeing 24 percent open rates, you found a window where your subscribers are actually reading email.
DST shifts those routines by one hour. The behavioral clock and the wall clock are temporarily out of sync. People who normally check email first thing at 7 a.m. are now biologically at 6 a.m. when the clock says 7. Their attention is not there yet.
In data terms: morning send windows between 7 and 10 a.m. typically see a 5 to 12 percent open-rate dip in the first week after DST, then recover by week two as habits adjust.
Evening windows are affected differently. Post-work email checks that happened around 6 to 7 p.m. are still happening at the same biological time, but the clock now says 7 to 8 p.m. If you are sending at 6 p.m., you may be catching people mid-commute rather than settled at home.
Why This Matters This Week
If you have a campaign going out this week, especially a promotional email or a time-sensitive announcement, you are sending into a disrupted window. That is fine as long as you account for it.
The businesses that lose the most to DST are the ones running on autopilot. They set their sends months ago, never adjusted them for season, and cannot explain why April campaigns underperform March ones.
Two weeks of attention now prevents that from affecting Q2.
Three Tactical Adjustments to Make Right Now
Adjust 1: Push send times 30 to 60 minutes later this week.
If you normally send at 9 a.m., try 9:30 or 10 a.m. This gives your subscribers a buffer for the behavioral adjustment. Run this for two weeks, then retest whether returning to 9 a.m. restores performance.
Adjust 2: Set up time zone sends if your platform supports it.
This is a one-time configuration that pays dividends every DST cycle and every campaign going forward. In Mailchimp, it is under Audience settings. In Klaviyo, it is in your send schedule options. In ActiveCampaign, it is under Campaign Scheduling. Every major platform supports it. If you have not done this yet, do it today.
Adjust 3: Run an A/B send time test before April.
Pick two send times 90 minutes apart. Send the same email to two equally sized list segments, one at each time. Check open rates after 24 hours. Rerun the test with the winner versus a third time. You will have a validated, post-DST best send time for your specific list before April campaigns begin.
A Note on Morning Sends
Morning sends, meaning 6 to 10 a.m. local time, are the most DST-sensitive. They are also typically the highest-performing window for B2B and professional service audiences, which includes most businesses in East Texas and Shreveport-Bossier markets.
The good news is the disruption is temporary. By March 22, most subscribers’ routines have stabilized and your morning send window returns to normal performance. If you have an important announcement or promotion to send, consider holding it until after March 22 unless timing makes that impossible.
What to Track This Week
Pull your open rate and click-through rate from last week’s send (pre-DST) and compare it to this week’s (post-DST) once the data is in. If you see a meaningful drop, that is the clock change, not a content problem. Do not panic and rewrite your subject lines.
If the drop is more than 15 percent and does not recover by week two, that is a signal your send time was already marginal and the DST shift just exposed it. That is the version of this situation where a send-time test is urgent.
Tying This to Email Strategy
Email timing is a small but compounding variable in your overall email performance. A list that opens at 28 percent instead of 22 percent over twelve months represents significantly more revenue from the same campaigns.
DST is a two-week calibration window, not a crisis. Make the timing adjustments above and you will be well-positioned for Q2 campaigns starting in April.
If you are building out an email marketing strategy or need help setting up segmented, automated sequences in your current platform, Starfish handles email marketing for East Texas and Shreveport-Bossier businesses. Call (903) 508-2576 or visit 140 E Tyler St Suite 200, Longview TX 75601.
Questions
worth answering.
Does daylight saving time actually affect email open rates? +
Yes, measurably. Email opens are tied to behavioral patterns: when people commute, eat breakfast, take lunch breaks, and wind down before bed. When the clock shifts an hour, those behaviors shift too, but not immediately. In the first week after DST, morning open rates between 7 and 9 a.m. tend to dip 5 to 12 percent because the biological clock has not caught up to the clock on the wall.
What is the best time to send marketing emails after DST? +
Push your send time 30 to 60 minutes later than your usual window. If you typically send at 9 a.m., try 9:30 or 10 a.m. for the next two weeks. Evening sends that previously worked at 7 p.m. may perform better at 7:30 to 8 p.m. while subscribers' post-work routines catch up to the new time. Re-test after two weeks when behavior has stabilized.
Should I segment my email list by time zone? +
If your email platform supports time zone segmentation, yes. This is standard capability in Mailchimp, Klaviyo, ActiveCampaign, and most major ESPs. Sending the same email to a subscriber in California at 9 a.m. Central means they receive it at 7 a.m. Pacific, which is too early for most professional audiences. Time zone-aware sends improve open rates consistently and the setup is a one-time configuration.
How long does the DST open-rate dip last? +
Typically 7 to 14 days. By the second full week after the clock change, behavioral patterns have largely adjusted and open rates return to their pre-DST baseline. If you have an important campaign to send, consider scheduling it for March 22 or later to avoid the adjustment window entirely.
How do I A/B test send times in my email platform? +
Most major ESPs, including Mailchimp, Klaviyo, and Constant Contact, include built-in send-time testing. Split your list 50/50 between your old send time and a new one. Run the test over 2 to 3 sends and compare open rates, not just for the first email but across all three. Send time effects compound: the right time trains subscribers to expect and open your emails.
What email metrics should I watch in the two weeks after DST? +
Watch open rate by send time cohort, click-through rate as a percentage of opens, and unsubscribe rate. An unusual unsubscribe spike after DST sometimes indicates timing misalignment: sending too early when subscribers are still asleep, too late when they have already checked email for the day. A clean open-rate baseline for your specific list is the most useful number to track.
Mindy Lewellen · CEO, Partner
Mindy leads strategy, client relationships, and creative direction at Starfish Ad Age. Based in Longview, Texas. Joined the agency in 2019.
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