The best time to post on Instagram on Sunday, from 712 posts

Sprout Social's advice for Sunday is to skip it: "Sunday is one of the worst days to post on Instagram." None of the five big timing studies puts Sunday among its best days. In this data Sunday came first of the seven, and its lead over Monday to Friday was large enough that luck is an unlikely explanation.

I pulled about a year of posts from 171 public Instagram accounts on September 22, 2026, and 712 of them went out on a Sunday. Each post was compared with its own account's usual post, so a two-million-follower account and a two-thousand-follower account count the same. On Sunday, posts did better than usual at almost every hour. The one exception was 6pm to 8pm ET.

At a glance

What is the best time to post on Instagram on Sunday?

No Sunday hour is clearly the best time to post on Instagram, because almost every Sunday hour ran above normal. The highest stretch, 8pm to midnight ET, scored 1.13x an account's normal likes, and midnight to 4am and noon to 4pm were close behind, both at 1.11x. None of them led the rest of Sunday by enough to rule out luck.

Sunday's lead over other days is biggest in the daytime, when the other days are weakest. From 8am to 4pm, other days run under normal and Sunday runs above. Over those eight hours together, Sunday's lead looked like more than luck, but only barely, and I picked those hours after seeing the data.

Buffer names 9pm, then 10pm and 8pm, and calls Sunday evenings "the strongest weekend window." All three fall in 8pm to midnight, Sunday's best stretch here, though Sunday's lead over other days' late evenings was small.

What could make this wrong: a few strong posts in a small stretch. Fewer than half of the 8pm to midnight posts beat their own account's usual post, and the late-evening high leans on the 11pm hour, which holds only a couple dozen posts.

What is the worst time to post on Instagram on Sunday?

The weakest Sunday stretch was 4pm to 8pm ET, at 0.97x an account's normal likes, the only Sunday stretch under normal. We couldn't tell whether that dip is real.

On the other six days, 4pm to 8pm is one of the better times to post, at 1.08x. On Sunday the hour curve dips under normal from 6pm to 8pm, lowest around 7pm, and accounts don't post much then: each hour from 5pm to 7pm holds 2% to 3% of Sunday posts.

Hootsuite names noon to 3pm and says to avoid Sunday "early mornings (before 8 AM) and evenings after 9 PM." Here both of those times did better than normal.

Is Sunday a good day to post on Instagram?

Sunday was the best day to post on Instagram in this sample, at 1.08x an account's normal likes, and its lead over the weekdays is unlikely to be luck.

Against Monday to Friday, Sunday's lead held up when I checked it. Against all six other days it came very close to holding up too, and Saturday and Sunday were too close to separate. Sunday also had the most posts beating their own account's usual post, half of them.

The earlier Instagram study, on the same accounts with fewer posts, had Sunday at exactly normal, fourth of seven. So two samples disagree on Sunday. This one is bigger, but a result that moved this much between samples is one to check on your own account before you rebuild a schedule around it.

Split by account size, the clearest lift came from mid-size accounts, 10k to 100k followers, and from the very biggest. Accounts under 10k sat right at normal on Sunday. The over-1M result comes from 7 accounts, and on Saturday it was the small accounts that carried the lift, so treat these splits as leads to check on your own account.

What do Buffer, Sprout Social, Hootsuite, and Later say about Sunday?

None of the five big Instagram timing studies puts Sunday among its best days, and Sprout calls it one of the worst. Each row quotes the study's own page as fetched on October 3, 2026.

On the day, this sample and the big studies point opposite ways. They leave Sunday out of their best days, and here it's the best of the seven. On the hour there's little to argue about. Every Sunday time the five name falls at a time that ran above normal here, and none names a time between 4pm and 8pm, the one stretch under normal. Even the two times Hootsuite says to avoid did better than normal.

The two methods can disagree without either being careless. The five studies add up engagement across many accounts, and Buffer, Sprout, Later, and SocialPilot say their times apply in the audience's own time zone. Added-up engagement can fall on a day when big or busy accounts post less or reach fewer people, even if the typical account's Sunday post does better than its other posts. This study compares each post with its own account and reports every time in US Eastern. None of the five pages says how many posts sit behind the hours it names, or how sure it is of them.

How I measured it

This uses the same posts as the Friday, Monday, Tuesday, Wednesday, and Saturday studies, looked at for Sunday. The accounts are public creators in 40 niches, found for the earlier Instagram study, and they range from small accounts to big ones. I took about a year of each account's posts and left out any under two weeks old, since those were still collecting likes. That left 5,734 posts from 171 accounts, 712 of them on a Sunday.

Each post was compared with that same account's usual post, so a big account's likes don't drown out a small one's, and the few posts that went viral were kept from deciding a whole time of day on their own. Every time is in US Eastern. I also checked how much each answer changed when a different mix of accounts was included. With a sample this size, a small difference between two times can still be luck.

The posts came through one Instagram endpoint on AnyAPI, instagram.user_posts, on September 22, 2026, and the whole crawl cost $0.53. Here's one page of it, on one account in the sample:

curl -sS -X POST https://api.getanyapi.com/v1/run/instagram.user_posts \
  -H "Authorization: Bearer $ANYAPI_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"handle":"_garden.ing"}'

{"output":{"data":{"posts":[{"id":"3988678296405120718","createdUtc":1789707527,"likes":804,"comments":217}],"nextCursor":"..."}},"costUsd":0.0008}

The sample: 69 accounts under 10k followers, 63 between 10k and 100k, 32 between 100k and 1M, and 7 over 1M.

What are the limits of this data?

This study measures likes only, in US Eastern time, on 171 public accounts that weren't picked at random.

• Likes only. Nothing here speaks to reach, saves, shares, comments, or follower growth, and Instagram's ranking leans on sends and saves more than likes.
• US Eastern for everyone. The accounts came from around the world, and none was matched to its audience's time zone. Sunday 3pm in New York is 9pm in Berlin, and Sunday 10pm in New York is already Monday in Europe.
• The best and worst times were picked after looking. That flatters them, and even so neither stood out from the rest of Sunday.
• Lots of comparisons. This study slices Sunday more than twenty ways, so one or two can look real by luck. The daytime result and Sunday's lead over the weekdays both held up, but neither by much.
• Two samples disagree. The earlier, smaller study had Sunday at normal. A result that moved from fourth to first between samples needs a third look.
• Patterns, not proof. An account that saves its best post for the weekend makes Sunday look good.
• Thin account-size splits. The over-1M result comes from 7 accounts.
• Not a random sample. The accounts came from niche searches a year ago, and a different set of niches could shift a result this size.

Sunday's lead over the weekdays is the one result here worth acting on. Within Sunday, the hour made little difference.

What should you change in your Sunday Instagram schedule?

In 712 Sunday posts, the day stood out against the weekdays, and no hour stood out within Sunday.

1. Don't drop Sunday because a big study calls it a weak day. Here it was first of seven, ahead of Monday to Friday.
2. Post at whatever Sunday hour suits you. Almost every Sunday hour ran above normal, and none clearly beat the others.
3. If you want a Sunday slot to test, test the daytime in your audience's time zone. 8am to 4pm ET is where Sunday's lead over other days was widest.
4. Check your own account once it has thirty Sundays. Pull your posts with instagram.user_posts, skip the newest twelve so you're not scoring posts that are still collecting likes, divide each post's likes by your typical post's likes, and group by day and hour in your audience's time zone. Ignore any hour with fewer than about ten posts. Four calls cost $0.0032.

The Saturday study found the other weekend day second of seven, the Tuesday and Wednesday studies found the hour made little difference on those days, and the Instagram study across all seven days uses the same method on the same accounts. The Instagram endpoints are what you'd use to rerun it on your own account.

Use data responsibly and follow AnyAPI's Acceptable Use Policy.