Calendar-driven birthday reminder. Reads today's events from your Google Calendar, filters by title prefix (default \"Birthday:\"), and sends a single summary to the owner. Generalizes to any annual milestone \u2014 change the prefix for anniversaries, holidays, work events.

`birthday-reminder-gcal`

Calendar-driven birthday reminder. Reads today's events from your Google Calendar, filters by a configurable title prefix (default Birthday:), and sends a single summary message to the owner once a day. Generalizes to any annual milestone — change the prefix to Anniversary: for wedding anniversaries, Work: for hire-date check-ins, Holiday: for personal observances, anything.

Why Calendar-driven, not Contacts-driven

The cleaner design would be to read birthdays straight from Google Contacts via the People API. That doesn't work today: gog (v0.19.0) does NOT surface the birthdays field on any of contacts list, contacts get, or people get (verified — --select "birthdays,..." returns {} even with the People API enabled in the GCP project). The auto-populated "Birthdays" sub-calendar Google can build from Contacts is also not reachable via gog (addressbook#[email protected] returns unrecognized calendar name).

Calendar events you create yourself ARE first-class. So this workflow uses that pattern. The bonus: the same workflow handles every other kind of annual reminder without modification — just change the prefix.

Use case

You forget birthdays. You feel terrible when you do. Setting a daily morning ping that reads "Today is Mom's birthday" buys you back the relationships dental-appointment automation already buys you back.

This is the personal-use cousin of appointment-reminder-gcal — same Calendar-reading pattern, different goal (reminding yourself vs reminding customers).

Setup

Credentials (Credentials view): - google-workspace — Google Workspace service-account JSON
Runtime environment (Runtime Environments view): - python — auto-created on every OS install
Calendar events — for each birthday/anniversary you want remembered, add an annual recurring all-day event to any calendar you own, with the title prefixed by your chosen tag: Birthday: Mom Birthday: Dad Birthday: Sarah K. Birthday: Mike (work) Anniversary: Jane & John Set each to repeat yearly. The workflow ignores the year and reads month/day.
Edit workflow.yaml — replace the three placeholders: - <<CALENDAR_ID>> — primary for your main calendar, or any calendar ID you own - <<BIRTHDAY_PREFIX>> — Birthday: (default), or Anniversary:, Holiday:, 🎂, etc. Match the prefix you use in event titles. Case-insensitive. - <<OWNER_PUBLISHER>> — user name linked to your contact (email, SMS, Slack, etc.)
Schedule the workflow once daily at 8:00 AM (or whenever you read your morning notifications).

Pipeline

find-today — runtimeenv (python). Queries Calendar for today's events via gog calendar events --today, filters events whose title starts with the configured prefix (case-insensitive), extracts the name from each (Birthday: Sarah K. → Sarah K.), and prints a formatted summary. Empty days print "No 'Birthday:' events today" and exit cleanly.
notify — message. Pipes the summary to the owner contact.

Sample output

Today is Friday, May 14, 2026.

2 people to remember:
  - Mom
  - Sarah K.

Reach out — a 30-second message lands harder than you'd think.

Customization

Multiple categories in one workflow — change the filter from a single prefix to a list. The script's prefix_l check can become an any(title.lower().startswith(p) for p in PREFIXES). One daily reminder covers birthdays + anniversaries + work milestones.
N days ahead — change --today to --days 7 to look a week out (gives you lead time to send a card). Update the summary text to reflect.
Auto-send greeting to the person — if the calendar event has an attendee with an email, the script captures it (see the attendees field in the matches). Add a gog gmail send --to <addr> --subject "..." --body "..." call inside the match loop. Caveat: many people put their own attendees on these events; that's themselves, not the celebrant. Test before broadcasting.
Different calendar per category — duplicate the workflow, point each copy at a different calendar ID and prefix. Keeps work birthdays separate from family ones.
Tone — edit the closing line in the script. Examples: drop it entirely; add "Cake suggestion: ..." with an AI step; pull a memory from a notes Sheet about the person.
Year-by-year deduplication — the current workflow has no state; running it twice in a day produces two notifications. Add a Sheet-based last-seen tracker (event_id | year_notified) if that matters. Most users just schedule it once daily and accept the trade-off.

Companion patterns

appointment-reminder-gcal — same Calendar-reading pattern for customer appointments
Make a copy of this workflow called anniversary-reminder-gcal (prefix Anniversary:)
Make a copy called work-milestone-gcal (prefix Work milestone:) for hire-date anniversaries

Verified

gog calendar events --today --cal <id> shape verified against the real Workspace account (2026-05-10): events return id, summary, start, attendees. The "no birthdays via People API in gog" gap was confirmed by direct testing — contacts list, contacts get, people get, and --select "birthdays" all return field sets without birthday data. That gap is the reason this workflow is Calendar-driven rather than Contacts-driven.

Source

See workflow.yaml.