When a Calendar or Event Misbehaves
Timezones, settings that live at a different level than you expect, and recurrence rules behaving literally.
Three things account for most of it.
The timezone you are reading. A calendar displays in its timezone, not yours, so a calendar set to another region shows hours that look wrong until you notice.
The level a setting lives at. Business hours are organisation-wide; holidays, event types, colours and intervals are per calendar. Looking for one at the other level is a common dead end.
Recurrence being literal. Monthly on the first Tuesday and every 4 weeks are different rules, and both do exactly what they say.
Known Issues
Every time on the calendar looks an hour or several hours out
You are reading a calendar whose timezone is not yours. Each calendar displays in its own timezone so that a shared calendar reads identically for everyone.
Check the calendar's timezone in its settings. If it is genuinely wrong, change it there — but be aware that changing it re-reads every existing event against the new timezone.
If the timezone is right and you simply work in another, add yours under Manage Custom Timezones so both appear on the grid.
A new calendar has nothing for anyone to book
Creating a calendar does not create a booking schedule, and the schedule is what produces the public booking page.
Open the calendar and use the schedule icon beside it to set one up. Until then the calendar still works for recording and protecting your own time — it just has nothing to offer anyone else.
The shaded non-working hours are wrong on every calendar
Those bands come from your organisation-wide business hours, not from the calendar you are looking at. Being wrong everywhere is the clue.
Open Define Your Business Hours and correct them there. The change applies to every calendar at once, and to everything that offers your time.
An event I dragged to a new time went back to where it was
The move did not save — usually a connection interruption at the moment of release.
Drag it again and wait for the confirmation before navigating away. If it keeps reverting, open the event and change its time in the panel instead, which gives you an explicit save.
A recurring series is landing on dates I did not expect
Monthly repeats by position — the first Tuesday, the third Thursday — not by date. Over a year that drifts well away from a fixed day number.
If you need a fixed date each month, build it as a Custom pattern instead of using the ready-made monthly option.
After saving any monthly or custom rule, move forward three or four occurrences on the calendar and check them. It is far cheaper than finding out from a guest.
Changing one occurrence of a recurring event changed all of them
A recurring event is one definition that appears many times, so a change to the definition reaches every occurrence.
For a one-off exception, keep it as its own separate event rather than editing the series. If a series genuinely needs to change partway, end the existing one on a date and create a new series from there.
A guest says they never got an invitation
Either Send Email Invite was off for that guest, or the event was created without them being notified.
Open the event and check that guest's Send Email Invite permission. Bear in mind that notifications for bookings made through a booking page have their own prerequisites, covered in the invites section.
A time I know I am busy is still being offered to people
The commitment is not on the calendar Zyntro reads. Business hours describe when you are generally open; they do not know about a specific meeting, leave or travel.
Put the commitment on the calendar as an event, including all-day events for leave and travel. Anything on the calendar blocks that time.
If the commitment lives in your personal Google or Outlook calendar, connect that calendar so its events are treated as busy time here.
A public holiday is on the calendar but people can still book it
Holidays are shown for visibility. They are not in themselves a block on your time.
Add an all-day event on the day as well. The holiday tells you it is a holiday; the event is what stops it being booked.
People can book outside my business hours
Business hours do not restrict bookings. They shade the calendar and inform how Zyntro judges sensible timing, but what a booking page offers comes from that booking schedule's own availability windows.
Open the booking schedule and set its availability to the hours you actually want to offer. That is the setting with teeth.
It is worth checking any schedule you set up some time ago, because a schedule offering an evening or a weekend will keep doing so no matter how you later change your business hours.
A private calendar with a password can still be opened by anyone
The password is saved but not yet enforced by the public booking page, as of October 2026.
Treat any booking link as public for now. If a calendar must not be bookable by the wider world, do not publish its link, and rely on which surfaces you share it through rather than on the password.
Two calendars show different event types and colours
Event types and category colours are per calendar, by design, so each calendar can use the vocabulary that suits it.
If you want them consistent, set the same types and colours in each calendar's settings. There is no single global list to change.
Troubleshooting Guide
Is the problem showing on every calendar, or just one?
Are the times wrong by a consistent offset?
Does the problem involve something repeating?
Frequently Asked Questions
Yes, but everything already on it will be displayed against the new timezone. If the calendar has a lot of history, read a few known events afterwards to confirm they say what you expect.
They describe when your organisation is open, which is a property of the business rather than of one calendar. Differences between calendars are expressed through booking schedules and events instead.
Yes. Bookings people made, and commitments imported from a calendar you have connected, occupy time exactly as events you added yourself do.
Set the series to end On a date rather than deleting it. Past occurrences stay as a record and nothing further is generated.
All Calendars lists them with their type and what is connected to each. The grid itself is per calendar, so comparing two means opening each.
