Send-Time Insights

When you send matters almost as much as what you send. Hober builds a best-time-to-send heatmap from your own audience's engagement history and surfaces it in three places: the Insights page, a one-click suggestion in the Composer's schedule picker, and a recommendation tool for connected AI agents.

Send-time insights are advisory: the platform shows you when your audience engages and suggests a time, but never silently moves your sends. You stay in control of the schedule.

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1. The heatmap

Open Insights in the dashboard and scroll to the Best time to send section: "Open rate by send hour and weekday — spot when your audience engages."

• The grid covers all 7 weekdays × 24 hours, in UTC, over the last 90 days of engagement.
• Cell intensity encodes the open rate for that weekday-hour bucket: opened ÷ delivered. Darker cells are stronger windows; the legend runs from Lower open rate to Higher.
• Hovering a cell shows the exact numbers, e.g. Tue 09:00 · 42% open · 210/500.
• Before you have engagement history the section shows: "No engagement data yet — the heatmap fills in as sends are opened."

The heatmap is computed from your delivered and opened engagement events. Buckets are keyed by when the delivery occurred, in UTC — there is no per-recipient timezone normalization in the chart itself (recipient timezones are handled at delivery time; see Quiet Hours, Frequency Caps & Consent).

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2. Reading it via the API

GET /api/v1/insights/heatmap?days=90
Authorization: Bearer <token>

• days — optional trailing window in days. Defaults to 90, capped at 365.

{
  "window_days": 90,
  "cells": [
    { "weekday": 2, "hour": 9, "delivered": 500, "opened": 210 },
    { "weekday": 4, "hour": 18, "delivered": 320, "opened": 96 }
  ]
}

Field	Description
window_days	The trailing window the counts cover.
cells[].weekday	0 = Sunday through 6 = Saturday, in UTC.
cells[].hour	Hour of day, 0–23, in UTC.
cells[].delivered	Deliveries that occurred in this bucket.
cells[].opened	Opens recorded in this bucket.

Buckets with no activity are omitted from cells — treat missing weekday-hour pairs as zero.

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3. Suggested send time in the Composer

When you schedule a notification for later, the schedule picker checks your heatmap and — once your audience has enough history — surfaces a suggestion:

Your audience engages most around Tue, 09:00 (your selected timezone)

Click Use this time to adopt it, or ignore it and pick your own time. The suggestion is the next upcoming occurrence of your strongest weekday-hour window, converted from UTC into the timezone you selected in the picker.

Two honesty rules apply:

• Suggestions appear only once your heatmap has at least 30 total opens; below that, the picker shows "Send-time suggestions appear once your audience has more engagement history."
• The suggestion is never applied automatically — scheduling always requires your explicit choice.

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4. Recommendations for AI agents

Connected agents get the same signal through the read-only MCP tool recommend_send_time (see Agent Access (MCP)). The tool returns:

• The top recommended send hours (UTC), ranked by your audience's opens
• The strongest weekday-hour windows with their open counts
• A sample_size and a plain-language note describing how trustworthy the recommendation is

When engagement history is too thin for the heatmap (fewer than 30 opens), the tool falls back to a delivery-rate heuristic over your recent campaigns and says so explicitly in the note — agents (and you) should treat that as weak evidence, not a pattern.

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5. What send-time insights do not do

• No automatic send-time optimization. There is no toggle that lets the platform pick or shift a job's send time on its own.
• No per-recipient send times. A job goes out at one scheduled time (fanned out per timezone group for recurring schedules); individual recipients are not each given their own optimized moment.
• Not a guarantee. The heatmap reflects when past sends were opened, which is partly a reflection of when you sent. Vary your send times occasionally so the data covers more of the grid.

Delivery controls still apply on top of any time you pick: quiet hours can defer a scheduled send per recipient timezone, and consent and frequency caps are enforced at delivery. See Quiet Hours, Frequency Caps & Consent.