NewReal-time mirroring for Microsoft 365 & Google

Be busyeverywhere.Be seen nowhere.

OnlyBusy mirrors your availability across every client's Outlook and Google calendar as native, private Busy blocks. Colleagues see when you're taken. Never why.

Start free for 14 days Try the live demo

No credit card · No IT admin needed · Event details never stored

Thu · Sep 25
091011121314
Dentist12:00 – 13:00
Unavailable12:00 – 13:00
External commitment12:00 – 13:00

Personal

Northwind

Contoso

“Dentist” scrubbedMirrored to 2 calendars · 0.8s

Shows up natively wherever your clients schedule

  • Google Calendar
  • Microsoft 365
  • Outlook Scheduling Assistant
  • Google Workspace
  • Exchange Online
  • Microsoft Teams
  • Google Meet
  • Outlook for Mac & Windows
  • iCloud · coming soon
  • Google Calendar
  • Microsoft 365
  • Outlook Scheduling Assistant
  • Google Workspace
  • Exchange Online
  • Microsoft Teams
  • Google Meet
  • Outlook for Mac & Windows
  • iCloud · coming soon
The problem

Fractional executives and consultants juggle three to six corporate calendars. Each one thinks you're free.

  1. Your clients don't use booking links.

    Internal teams open Outlook's Scheduling Assistant or Google's Find a time. Calendly and Cal.com never enter the picture.

  2. So your other commitments are invisible.

    Your dentist, your other client's board meeting, your kid's recital: none of it exists in their tenant. You look free. You get double-booked.

  3. OnlyBusy fills the gaps with native Busy.

    Real events in their calendar, marked Busy and private. Their scheduling tools just work, and they never see a single detail.

OScheduling AssistantContoso · Thursday
910111213141516

Anna Weber

Head of Finance

Ben Ortiz

Controller

You

Fractional CFO

Suggested time11:00 · you're actually at the dentist
Live demo

Click an empty slot on any calendar. Watch OnlyBusy scrub it and block the same time everywhere else, under whatever name you choose.

Click a slot to add, click an event to remove

Personal

Northwind

Contoso

910111213141516
Busy14:00 – 15:00
Unavailable11:00 – 12:00
Unavailable14:00 – 15:00
External commitment11:00 – 12:00

Sync log

Add an event to see what OnlyBusy reads and writes.

Edit what each client sees in the calendar headers. The real title never leaves its source.

Features

Built for people whose clients live in locked-down Microsoft 365 and Google Workspace tenants.

Native availability injection

Real calendar events, not read-only ICS feeds. Scheduling assistants see you as genuinely Busy, instantly.

Anna Weber
Ben Ortiz
You

Outlook Scheduling Assistant · Google Find a time · Teams

Real-time, not next-day

Push notifications from Google and Microsoft. ICS subscriptions take 6–24 hours.

<90s

from change to Busy

Zero-leak scrubbing

You see the real title. Guests, notes, and that title never cross onto another calendar.

Client sees

Therapy · Dr. Klein

Smart masking per calendar

Each calendar shows the label you pick, from a plain Busy to External commitment.

Northwind: UnavailableContoso: External commitmentPersonal: Client work

Buffers between clients

Auto-pad cross-client calls so back-to-backs never collide.

Northwind+10mContoso

Loop-proof by design

Every mirrored block carries a private marker and is tracked by id, so it can never echo back into a duplicate.

evt_7f3a→busy ✓ marked→re-sync

No IT admin required

Personal OAuth with minimal scopes, the same consent any calendar app asks for.

  • Calendars.ReadWrite
  • offline_access
  • calendar.events
  • calendarlist.readonly
Zero-leak architecture

OnlyBusy asks Google and Microsoft for exactly four fields. Your client gets a private placeholder with no guests, no notes, and no location.

Your event

Stays in your personal calendar

{title: "Therapy · Dr. Klein"attendees: ["you", "dr.klein@…"]location: "Praxis Mitte, 2F"notes: "Bring insurance card"start: "14:00"end: "15:00"showAs: "busy"}

What OnlyBusy requests

Title for your view. Notes, guests, and location stay behind

{id: "evt_7f3a"title: "Therapy · Dr. Klein"start: "14:00"end: "15:00"busy: true}

What Contoso sees

A native, private Busy event

{subject: "External commitment"start: "14:00"end: "15:00"showAs: "busy"sensitivity: "private"attendees: []}

Encrypted tokens

OAuth tokens are sealed with AES-256-GCM before they touch the database.

Times, not content

Only start and end of mirrored blocks are stored, so updates stay idempotent.

Clean exit

Disconnect an account and every Busy block it created is removed from every calendar.

Why OnlyBusy

Cross-platform availability with near-instant sync and hard privacy guarantees. No project management suite attached.

Calendly · Cal.comRelies on booking links. Doesn't help the colleague looking at Outlook's Scheduling Assistant.Native Busy, any tenant
MotionExpensive and bundled with full task and project management when you only need availability.Native Busy, any tenant
Reclaim · ClockwiseFocused on a single Google workspace; clunky across separate Microsoft 365 tenants.Native Busy, any tenant
SyncGene · CalendarBridgeComplex setup, slower sync, or elevated admin privileges freelancers can't get.Native Busy, any tenant
Pricing

Every plan starts with a 14-day trial of everything. No credit card.

Pro

Specialist freelancers and consultants

$99/yr
  • Up to 4 synced calendars
  • Real-time sync
  • Custom title per calendar
  • Automatic buffers
Start 14-day trial
Most popular

Fractional

CFOs, CMOs and CTOs across 3–6 companies

$199/yr
  • Unlimited calendars
  • Everything in Pro
  • Conditional rules (e.g. no weekend blocks)
  • Conflict alerts on your phone
Start 14-day trial

Team

Agencies placing staff with clients

$10/seat/mo
  • Central billing
  • Per-consultant workspaces
  • Everything in Fractional
  • Priority support
Start 14-day trial
FAQ

Anything else? We reply within a day.

Connect your calendars in two minutes. Your availability does the rest.

Start your free trial