3CX Holiday Scheduling for MSPs: Manage Every PBX From One Calendar

The chore nobody schedules time for

Every MSP managing more than a handful of 3CX servers knows this drill. Thanksgiving is next Thursday, or the office is closing early on Christmas Eve, and now someone has to go into each customer's PBX, navigate to the right office-hours group, and add a holiday entry so the after-hours greeting and routing kick in on the right day. Twenty customers means twenty logins. Fifty means an afternoon.

And it's not a one-time setup. New customers onboard. Clients decide last-minute to close for a regional holiday you didn't have on your list. A one-off "closed for the team offsite" entry from last March is still sitting on the PBX, cluttering the schedule. The work never quite finishes — it just comes back around the next long weekend.

The fix is to stop treating each PBX as its own island. Sikurd's Holiday Scheduler turns "log into every server" into "manage one calendar," and then goes one step further: it lets your customers submit their own holiday hours, so you're approving requests instead of chasing emails.

How the Holiday Scheduler works

The model is deliberately simple: you author a holiday once on the Sikurd side, then apply it wherever you want. Sikurd keeps the template as the source of truth and remembers which Holiday it created on each PBX, so later edits and deletes target the right entry on the right server.

1. Build a template

A holiday template is just the holiday, described once:

Recurring or one-off
An annual holiday like New Year's Day recurs every year (3CX stores it with no concrete year). A one-time "closed for inventory" is a single-date entry.
Start and end date/time
Full-day or partial — close at noon on Christmas Eve, reopen the morning after Boxing Day. The times carry through to every PBX.
An optional greeting
Attach a WAV and Sikurd uploads it to each PBX's custom-prompt library on apply, then points the holiday at it so callers hear the right message. (Pair it with Voice Studio to generate one.)

2. Apply it to one PBX — or fifty

Pick the template, select your target instances, and push. For each one, Sikurd resolves that PBX's default office-hours group — looked up live by its IsDefault flag rather than a hard-coded group number, because that number genuinely differs between installs — and creates the 3CX Holiday there.

Crucially, you get a per-instance result, not a fire-and-forget. If a server was unreachable or not connected, Sikurd tells you "applied to 3 of 4" and lets you retry the one that failed. And re-applying a template you've already pushed is treated as a re-sync — Sikurd updates the existing Holiday in place rather than stacking duplicate entries on the PBX. Edit the template later and re-push; every instance stays in lock-step.

3. Clone from the curated library

Most holidays aren't bespoke — they're the public holidays for a country. Instead of looking up the date of the next bank holiday, Sikurd ships a curated Holiday Libraryyou filter by region group (North America, UK & Ireland, EU, Nordics, APAC), country, and year. Find the set you need and clone it into templates in a couple of clicks. The dates come pre-loaded; you decide where to apply them.

4. Keep it tidy automatically

One-off holidays accumulate. Sikurd has an opt-in auto-prune: turn it on and Sikurd deletes one-off holidays whose end date is more than a week in the past — across your whole fleet — and re-runs the sweep hourly so it stays clean. Recurring and annual holidays are never touched (they have no "past" to expire). Because pruning deletes on the live PBX, enabling it asks for a confirmation and runs an immediate first sweep, and every deletion is written to the audit log.

The part that actually saves you time: customers submit their own hours

Here's the workflow most MSPs don't realize is possible. The slow part of holiday management often isn't the clicking — it's the back-and-forth. "Are you closing for Good Friday?" "What are your hours the week between Christmas and New Year's?" You email the client, they reply three days later, you translate that into PBX entries.

Sikurd collapses that loop into a link. For any instance, you mint a public holiday-request link: a long, random, unguessable token — no login, no account for the client. You send it over. They open a clean, branded page (it shows your MSP name, so it looks like part of your service), pick their holidays from the curated regional library, and submit.

You stay in control — it's a request, not a change
A client submission never touches the PBX. It lands in your inbox as a pending review. You approve it, and only then does Sikurd build the templates and apply them to that client's instance.
Clients can't go off-script
The public form only offers the curated library — no free-text holidays. Submissions stay predictable, and a client can't invent an entry that breaks your routing.
Scoped and safe by design
The link is tied to one instance. The client never sees a login, your other customers, billing, or any PBX setting. Links expire (you choose how long, up to 90 days) and stop accepting input once submitted, so a request can't be changed out from under the admin reviewing it.
Unguessable, and quiet about failures
Tokens are 32 bytes of randomness. A bad, expired, or already-used link returns the same generic "not available" response — an attacker fishing for valid links learns nothing.

The public submission page lives at a path like /holidays-request/<token>. Everything the client does there is logged on the instance's audit trail — link created, request submitted, request applied — so you have a clean record of who asked for what and when.

Why this matters at fleet scale

For a single PBX, doing holidays by hand is mildly annoying. Across a book of customers, it's a recurring tax on your team's time and a real source of "oops, we forgot to set the holiday and calls rang into an empty office" incidents — the kind that generate an angry call from the customer and an apology from you.

Centralizing the calendar removes the per-PBX logins. The library removes the date lookups. The customer links remove the email chase and, just as importantly, remove you as the bottleneck while still keeping you as the approver. Nothing reaches a customer's phone system without an admin signing off — but the busywork that used to surround that approval is gone.

Getting started

Holiday Scheduler is part of the core platform — there are no tiers and nothing about holidays is locked behind an upgrade. Your first three 3CX instances are free forever (the whole platform, not a trial), so you can wire up a few customers and run a real holiday through it before you pay for anything. Beyond three instances you're billed simply per instance.

A practical first run:

Connect a couple of instances
Add two or three customer PBXs so you can see a true multi-instance apply.
Clone next quarter's holidays from the library
Filter by your customers' country, clone the set, and apply to the relevant instances in one pass.
Send one customer a request link
Pick your most schedule-fussy client, mint a link, and let them submit their own hours. Approve it from your inbox and watch it land on their PBX.
Turn on auto-prune
Flip it on once so last year's one-off entries clean themselves up going forward.

Frequently asked questions

What exactly does the Holiday Scheduler push to 3CX?

A standard 3CX Holiday, attached to each PBX's default office-hours group. You build the holiday once in Sikurd as a template — recurring or one-off, with a start and end date/time and an optional greeting — and Sikurd creates the matching Holiday on every instance you target. It resolves each PBX's default group automatically (by IsDefault) rather than assuming a fixed group number, because that number varies between installs.

Can I apply one holiday to many customers at once?

Yes — that's the core of it. Pick a template, select one instance or fifty, and Sikurd pushes the holiday to each in turn. You get a per-instance result ("applied to 3 of 4 — one PBX wasn't reachable, click to retry"), and re-applying an existing template re-syncs the holiday in place instead of stacking duplicates on the PBX.

How does the customer self-service link work?

For any instance you can mint a public holiday-request link — a long, unguessable token, no login required. You send it to your client; they open a branded page showing your MSP name, pick their holidays from the curated regional library, and submit. The submission lands in your inbox as PENDING review. Nothing touches the PBX until you approve it. Bad, expired, or already-used links all return an identical "not available" response, so the token can't be fished for.

Do clients get to type in arbitrary holidays or change my PBX directly?

No. The public form only lets clients pick from the curated holiday library — no free-text entries — and submitting never writes to the PBX. It creates a request for you to review. When you approve it, Sikurd turns each selected holiday into a template and applies it to that client's instance. The client never sees a login, your other customers, or any PBX setting.

What about old one-off holidays piling up on every PBX?

There's an opt-in auto-prune. When enabled, Sikurd removes one-off holidays whose end date is more than a week in the past, across your fleet — and re-checks hourly so it stays tidy. Recurring/annual holidays are never pruned (they have no "past"). Turning it on runs an immediate sweep, with a confirmation first because it deletes on the PBX right away, and every prune is audit-logged.

Does it support a holiday greeting / audio prompt?

Optionally, yes. A template can carry greeting audio; when you apply it, Sikurd uploads that WAV to each PBX's custom-prompt library and points the holiday at it, so callers hear the right message. Re-syncs are smart about it — if the same audio is already on a PBX, Sikurd reuses it instead of re-uploading.

Is there a free tier?

Yes. Your first three 3CX instances are free forever — the full platform, Holiday Scheduler included, no credit card. You only pay per instance beyond the first three. Every feature is included on every account; there are no tiers and nothing about holidays is gated.