Generally, the best times to post are 8am, 1pm, and 5pm. But it is different for every account. You can find your account’s best time to post by going to your profile → insights → total followers → scroll all the way down → when your followers are most active. The longest bar is your ‘Peak Time’, aka when your followers are most active on the app. The best time to post is 15-30 minutes before your peak time.