How to Set Work Anniversary Reminders in Slack

Set a private work anniversary prompt in Slack, use a yearly calendar event for recurrence, or compare a date-aware celebration digest. Includes a simple handoff checklist.

By Kelasa team · November 6, 2026

To remember a colleague's work anniversary in Slack, set a private reminder for the next date and renew it each year, or create a yearly calendar event and use that as your recurring prompt. A scheduled Slack workflow can remind a coordinator to check a list, but it does not discover hire dates on its own. Ask the colleague whether they want a public celebration before posting one. These are documentation-backed approaches, not steps we tested in a Slack workspace.[1][2][3]

Decide what the reminder needs to do

A work anniversary is based on a hire date, not a birthday. Decide whether you only need a private nudge to write a note, a prompt for a coordinator to review several upcoming anniversaries, or a channel celebration. A single all-team reminder may be too public if someone prefers no announcement. Keep the full hire-date list access-restricted; record an opt-in preference and an owner for each announcement. For a lightweight greeting, see our birthday celebration etiquette guide—the same consent-first principle applies to anniversaries.

For example, a fictional internal roster could contain Alex · June 12, 2022 · public greeting: yes · coordinator: Priya. Those details belong in a restricted roster, not in a public recurring message. A real anniversary needs a hire year if you want to say “four years”; a month and day alone are enough only for a date prompt. Check whether the hire date is accurate and whether the person wants the year or milestone mentioned.

Method 1: Set a one-off Slack reminder

Slack currently documents custom personal reminders as to-dos: on desktop, open To-dos → Add To-do, enter a private task, click Add reminder, choose a time (or Custom for the next anniversary date and time), and click Add.[1] An example task is “Check Alex's anniversary preference and prepare a note.” Inspect the date Slack displays; this is a one-off reminder, not a verified yearly recurrence. After it fires, create the next year's reminder or use a recurring calendar event to avoid depending on a hand-maintained renewal.

Slack also documents /remind [#channel] [what] [when] for channel reminders, but those messages appear in the channel. Do not put someone's name, hire date, or milestone in a broadly visible channel reminder unless they agreed to that disclosure. Slack's reminder help documents day-based repeats such as every Monday, not a guaranteed annual /remind phrase; confirm the next occurrence if you experiment with one.[1] Our recurring birthday reminders guide explains the same annual-date problem in more detail.

Method 2: Use a yearly calendar event

In Google Calendar on a computer, create a private event for the anniversary, choose the control beside Does not repeat, set a yearly recurrence if offered, and save. Google's recurring-event help describes that repeat control; check the next occurrence and set an advance notification so there is time to prepare a message.[2] Keep the event on a restricted calendar and use a neutral title if other people can see its details. For a hire date on February 29, agree on a non-leap-year policy with the employee rather than assuming the calendar chooses your preferred substitute date.

Slack's Google Calendar app help describes personal event notifications and notification preferences.[3] Connecting the app requires installation and configuration in your workspace. A calendar notification in Slack is not an automatically written work-anniversary greeting; verify which calendar is connected, when the notification arrives, and what event details could be exposed before enabling any channel-facing option.

Method 3: Schedule a coordinator check

If multiple anniversaries need review, Slack's scheduled-message workflow template can send a fixed prompt to a private channel on the schedule you choose.[4] For example: “Review the restricted anniversary roster for the coming week; confirm opt-in before posting.” It cannot infer which person has an anniversary from that message alone. Slack says Workflow Builder is on paid plans and administrators can restrict access.[5] Our Workflow Builder birthday-reminder walkthrough covers setup and checks for this same coordinator-prompt pattern, not automatic date matching.

A simple announcement and handoff checklist

Before the date: Confirm the hire date, consent, preferred channel, spelling, and whether a milestone count is welcome.
On the agreed day: Have one designated person send the greeting. For example: “Happy work anniversary, Alex! Thanks for everything you bring to the team.” Personalize it only with details the colleague is comfortable sharing.
After posting: Mark the celebration handled in the restricted roster so a calendar alert and a Slack prompt do not trigger two messages.
When ownership changes: Transfer the roster, reminder ownership, opt-out choices, and upcoming dates. Remove access for departing coordinators.

Time zones and weekends need a team policy: decide whether you celebrate on the exact date or a workday and avoid surprising someone with a weekend notification. A reminder is only as reliable as its owner and its underlying date list.

When a date-aware app makes sense

If renewing individual prompts or maintaining a coordinator check is burdensome, compare your process with Kelasa BirthdayBot's overview. The current landing page describes a daily Slack digest for birthdays and work anniversaries, with a chosen channel, schedule, and workspace time zone. That is not a promise that Slack profiles automatically provide hire dates or that an anniversary is shifted off a weekend. Confirm the product's current setup, consent controls, and preferred date behavior before entering real employee information. For a small team that wants human approval of every greeting, the private calendar approach may be simpler.

Sources and editorial limits

These instructions rely on published help pages, not hands-on Slack or calendar testing. There are no original screenshots or tested reminder confirmations here; verify the controls, recurrence, permissions, and notifications in your own workspace before relying on them.