Frequently asked questions about Hetk calendar sync. If yours isn’t here, email us.
Getting started
Which calendar providers does Hetk support?
Google Calendar, Microsoft Outlook (Office 365 and Exchange Online included), and Apple iCloud. We’re adding CalDAV, Proton Calendar, and FastMail next.
What kinds of accounts work?
Personal Gmail, Google Workspace, Outlook.com, and Microsoft 365 (work and school) all work. For Apple iCloud, you connect with an app-specific password you generate in your Apple ID settings.
Can I sign in with more than one Google or Microsoft account?
Yes. Link a second Google or Microsoft account from Settings → Accounts, and from then on you can sign in with either one — you’ll always land in the same Hetk account, with all the same calendars and sync relationships. There’s no separate admin or team login; every linked account is just another way in. Apple iCloud is a bit different: it connects for calendar sync only, so it can’t be used to sign in.
How long does the first sync take?
Usually under a minute. Calendars with thousands of events can take a few minutes. After that, new and updated events propagate in seconds over webhooks.
Do I need to install anything?
No. Hetk runs in the cloud. You connect your accounts at app.hetk.io once, and sync runs in the background. Nothing to install on any device.
What if my IT admin blocks third-party calendar apps?
If your tenant requires admin approval for new OAuth apps, you’ll see an “admin approval required” message when you try to connect Outlook. It’s a short request your admin can grant in a few clicks. Walkthrough of the message and what your admin is being asked.
What happens during the 21-day free trial?
You get full access to every feature on either plan. No card is needed to start. If you don’t add one, the trial ends, your syncs pause and nothing is charged. If you add a card during the trial, your plan is charged when the trial ends and renews automatically until you cancel.
How sync works
Is sync one-way or two-way?
Both. You pick a direction per sync relationship. One-way mirrors a source calendar to a target. Two-way (bi-directional) copies new events both ways, and an edit to an original updates its copy. An edit to a copy is put back to match the original.
Can I choose which events sync?
Yes, with filters. A filter is a “skip” rule on a sync: events that match it stay in their own calendar. A rule can match all-day events, events that show you as free, invitations you answered “Maybe” to, events whose title contains a word or phrase, or a color (a color you gave a Google Calendar event, or an Outlook category; iCloud events have no color to match). A rule skips an event only when everything you filled in on it matches, and an event is skipped if any rule matches. On a two-way sync you set rules for each direction. There is also a switch, “Only events created in this calendar”, that stops events which arrived from another sync from being copied on. The week preview redraws as you change a rule, and when you change the rules on an existing sync, Hetk tells you how many copies it will remove or put back before you save. Filters are included in both plans.
Can I merge multiple calendars into one view?
It depends what you mean by “merge”. Most calendar apps already let you display multiple calendars side by side, which is a unified view, not sync. If you want changes made in one calendar to actually appear in the others, that’s what Hetk does. The four common approaches and where each one fits.
Can I subscribe to a calendar in read-only mode instead of syncing it?
Yes, through your provider’s native ICS or webcal support. It’s free and simpler than full sync, but slower to update (often hourly) and read-only. Step-by-step instructions for Google Calendar and Outlook. Reach for Hetk when you need real-time updates, or want events made in either calendar to show up in both.
How quickly are new events propagated?
Changes in Google Calendar and Outlook usually arrive within seconds, through push notifications. A safety check runs every 15 minutes in case a notification is missed. Apple iCloud has no push. Hetk checks iCloud every 5 minutes, and less often for a calendar that has been quiet. See how sync timing works.
What happens if I edit the same event in two calendars at once?
The original wins. Each synced event has one original, in the calendar where it was made; the other calendar holds a copy. Edits to the original update the copy. An edit to the copy is put back to match the original, usually within a few hours. So to change an event, edit the original.
Are recurring events and exceptions handled correctly?
Yes. Hetk syncs the full recurrence rule and tracks individual exceptions (a single moved or cancelled occurrence), so the series matches across calendars.
Are attendees, attachments, and meeting links synced?
Event time, title, description, and location sync by default. Attendee lists and meeting links (Zoom, Teams, Meet) stay on the source side. Attachments don’t sync; they stay on the source calendar to avoid permission and storage issues.
How are time zones and all-day events handled?
Hetk preserves the event’s original time zone instead of converting it. All-day events stay all-day across providers. Daylight saving transitions work because we store IANA time zone identifiers, not raw offsets.
Privacy and data
Is my calendar data safe?
Yes. Hetk connects via OAuth 2.0 (Google, Microsoft) or app-specific passwords (Apple), so we never see your provider passwords. Data is encrypted in transit (TLS 1.2 or newer) and at rest (Azure SQL with TDE). OAuth tokens are encrypted before storage. Full detail on our security page.
What event details does Hetk actually store?
Only what’s needed to sync. We store OAuth tokens and per-event sync metadata: event IDs, ETags, start and end times, and sync timestamps. We do not store event titles, descriptions, locations, or attendee lists.
Can I sync a work calendar to a personal one without exposing meeting titles?
Yes. The Replace the details with “Busy” setting strips event titles to “Busy”, clears descriptions and locations, and leaves only the time block on the target calendar. Good for showing availability without leaking meeting details.
Can I label synced events so I know which calendar they came from?
Yes, with a title template. Set a rule like [Job 1] {{original_title}} on a sync, and every event arrives prefixed. Combined with the Replace the details with “Busy” setting it renders as “[Job 1] Busy”, so you can tell two clients or two jobs apart at a glance without exposing any meeting detail. It’s literal text substitution, not AI. See how to label synced calendar events by source.
Who can see my synced events?
Only the people who already have access to the calendars you connect. Hetk doesn’t publish events anywhere or share data with third parties. Synced events inherit the visibility settings of the target calendar.
Is Hetk GDPR compliant? Where is my data stored?
Yes. Hetk Technologies OÜ is based in Estonia (EU). Hetk stores your data in the EU (Microsoft Azure, North Europe). Payment, network and email processors such as Stripe, Cloudflare and Google may process some data outside the EU under their own data-transfer safeguards. We’re subject to GDPR and Estonian data protection law.
What happens to my data if I delete my account?
Deleting your account removes your account, connections, tokens and sync records at once. The few records listed in section 8 of our Privacy Policy are kept, and backups and logs expire within 90 days. Events already synced to your calendars stay there as regular calendar events; we can’t remove those retroactively.
Pricing and billing
How does billing work?
Monthly or annual on both plans. You start with a 21-day free trial, no credit card required. When you subscribe, Stripe handles the payment. Annual saves up to 38% over monthly.
What’s the difference between Personal and Professional?
Same features on both: bi-directional sync, privacy controls, filters, real-time webhooks, all three providers. The only difference is the sync pair limit (Personal: 3 sync pairs, Professional: 8 sync pairs).
Why early-adopter pricing? Will it go up?
Early-adopter pricing ($10/yr Personal, $35/yr Professional) stays at that price as long as you don’t cancel. Standard pricing ($15/yr Personal, $50/yr Professional) applies to new customers once the early-adopter window closes.
Can I cancel my subscription?
Anytime, from the billing portal. Your subscription stays active until the end of the current billing period. No cancellation fee, no contract.
Do you offer refunds?
The 21-day trial usually makes refunds unnecessary. If you hit a problem and a refund feels fair, email [email protected] and we’ll take a look.
Troubleshooting and limits
My events aren’t syncing. What should I check first?
Open the sync detail page at app.hetk.io to see the latest status, last successful sync, and any error messages. The most common cause is an expired OAuth token. If you see a “reconnect” prompt, click it and re-authorize. Still stuck? Email [email protected].
Why am I being asked to reconnect my Google or Microsoft account?
OAuth tokens expire periodically, especially after a password change, MFA reset, or extended account inactivity. Reconnecting takes a few seconds and restores sync immediately. Hetk banners the app the moment a token fails, well before sync falls behind.
I see duplicate events. How do I fix that?
Duplicates usually mean an event existed in both calendars before you set up sync. Hetk tracks events it synced via internal IDs, but pre-existing duplicates have to be cleaned up by hand. Once you do that, future events stay in sync without duplicating.
Can I sync calendars I don’t own (shared, subscribed, holiday)?
Shared calendars: yes, if the provider grants you write access. Subscribed calendars (.ics URLs) and holiday calendars are read-only, so they can be a source but not a target.
How many calendars and sync relationships can I have?
Both plans support unlimited calendars. Personal plan supports up to 3 sync pairs; Professional supports up to 8 sync pairs. You can build any combination of one-way and two-way syncs within your plan’s sync pair limit.
Roadmap and company
Do you offer team plans?
No. Team plans do not exist yet. Hetk is for individuals.
Will you add CalDAV, Proton, FastMail, or Yahoo support?
CalDAV (Proton Calendar, FastMail) is next on the roadmap. Yahoo is on the maybe pile. If yours isn’t listed, email [email protected]. The provider with the most requests goes next.
Who builds Hetk?
Andrei Reinus, a software engineer based in Estonia, under Hetk Technologies OÜ. One person, focused on doing calendar sync well instead of building a platform with features nobody asked for. More on the about page.