Day of week moves the needle about 1.5 times. Length moves it 4.5 times

What we can actually measure

Every reel we analyse carries its posting timestamp, so we can group 2,543 of them by the day they went out. That is more than most advice on this topic is built on.

What we deliberately will not show you is time of day. Timestamps are stored in UTC and the creators are spread across the world, so an hour column would be comparing a 9am post in London with a 9am post in Los Angeles as though they were the same thing. Any page giving you an hour without knowing your audience's timezone is guessing.

Posting day, measured

Sunday has the best clear rate at 23.7 percent and Thursday the worst at 16.2 percent. Weekends and Monday do better than midweek, which is the opposite of the advice usually given, and Wednesday has the lowest median views in the table at 91,814.

Now the part that stops this being useful

The spread between the best and worst day is about 1.5 times on clear rate. The spread between length bands is 4.5 times on median views: 48,548 for Reels under 15 seconds against 217,962 for 15 to 30 seconds.

So posting day is real and it is third-order. If you are choosing between fixing your posting schedule and fixing your video lengths, the lengths are worth roughly three times more attention, and they are entirely under your control.

What would make the day column misleading

1. We cannot see each account's audience timezone, so a 'day' is the creator's posting day, not the audience's viewing day.
2. Creators choose their days. If stronger creators happen to favour weekends, the day column is partly measuring who posts when.
3. Sample sizes per day run from 271 to 424, so single-point differences of a percentage point or two are noise.

What to do

1. Post when you can post consistently. The difference between your best and worst day is smaller than the difference between posting and not.
2. Fix length first. It is the biggest measurable lever in our data.
3. If you want to test timing, test it on your own account over at least twenty Reels, because your audience's timezone is the variable we cannot see.
4. Treat any guide quoting a specific hour with suspicion unless it knows where your audience lives.

Figures on this page come from 2,543 Instagram Reels across 534 accounts, analysed by Scrptly and deduplicated so no reel is counted twice. Read 2026-10-13.