Add recurring series to events

A Series checkbox under When opens a panel for the schedule:
weekly on chosen weekdays, monthly by date, or monthly by weekday
position, every N weeks or months, with meeting times and an
optional meeting count. starts_on anchors the schedule and ends_on
bounds it, so effective_status needs no change.

Occurrences are derived, not stored. src/lib/eventSeries.ts builds
the schedule label shown on cards and the event page, and the
upcoming dates listed on the event page.

Migration 016 adds the columns; the CRUD engine gains a time type.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

server/src/admin-crud.js

@@ -34,6 +34,7 @@ export class HttpError extends Error {
 
 const SLUG = /^[a-z0-9][a-z0-9-]{0,63}$/;
 const ISO_DATE = /^\d{4}-\d{2}-\d{2}$/;
+const CLOCK_TIME = /^([01]\d|2[0-3]):[0-5]\d$/;
 
 /* Not a value the caller can ever send, so it can mean "leave this
    column out of the statement" without colliding with real data. */
@@ -98,6 +99,13 @@ function coerceValue(column, raw, errors, prefix = "") {
       if (!ISO_DATE.test(value)) errors[key] = "Use YYYY-MM-DD.";
       return ISO_DATE.test(value) ? value : null;
     }
+    case "time": {
+      // <input type="time"> sends HH:MM, or HH:MM:SS when a step
+      // asks for seconds. Nothing here does, so seconds are dropped.
+      const value = String(raw).trim().slice(0, 5);
+      if (!CLOCK_TIME.test(value)) errors[key] = "Use HH:MM, 24-hour.";
+      return CLOCK_TIME.test(value) ? value : null;
+    }
     default: {
       const value = String(raw).trim();
       return value === "" ? null : value;

server/src/admin-schema.js

@@ -40,6 +40,7 @@ const int = (name, opts = {}) => ({ name, type: "int", ...opts });
 const real = (name, opts = {}) => ({ name, type: "real", ...opts });
 const bool = (name, opts = {}) => ({ name, type: "bool", ...opts });
 const date = (name, opts = {}) => ({ name, type: "date", ...opts });
+const time = (name, opts = {}) => ({ name, type: "time", ...opts });
 const enumeration = (name, values, opts = {}) => ({
   name,
   type: "enum",
@@ -281,6 +282,10 @@ const organizations = {
 
 /* ── Events ──────────────────────────────────────────────────── */
 
+/* Column suffixes for the series weekday flags, Sunday first to
+   match Date#getDay. */
+const SERIES_WEEKDAYS = ["sun", "mon", "tue", "wed", "thu", "fri", "sat"];
+
 const events = {
   key: "events",
   table: "events",
@@ -339,6 +344,18 @@ const events = {
     bool("is_published"),
     int("sort_order"),
     bool("in_timeline"),
+
+    // A repeating schedule. Columns rather than a side table: the
+    // schedule is always exactly one per event, and the public view
+    // is SELECT e.*, so it reaches the site with no join. Ignored
+    // while is_series is 0. See migration 016 for what each means.
+    bool("is_series"),
+    enumeration("series_frequency", ["weekly", "monthly_date", "monthly_weekday"]),
+    int("series_interval"),
+    ...SERIES_WEEKDAYS.map((day) => bool(`series_${day}`)),
+    time("series_start_time"),
+    time("series_end_time"),
+    int("series_count"),
   ],
 
   extensions: [timelineExtension("event")],

server/src/migrations/016_event-series.sql

@@ -0,0 +1,73 @@
+-- ═══════════════════════════════════════════════════════════════
+-- EVENT SERIES
+--
+-- An event that meets on a schedule — a weekly class, a monthly
+-- meeting — is still one row. is_series says the dates repeat; the
+-- series_ columns say how. Occurrences are never stored: they are
+-- a pure function of these columns plus starts_on and ends_on, and
+-- the site works them out when it draws them.
+--
+-- The event's own dates bound the series. starts_on is the first
+-- meeting and anchors everything else: which week an every-other-
+-- week series is "on", which day of the month a monthly one keeps,
+-- and which weekday it falls on when no day is ticked. ends_on,
+-- when set, is the last day it can meet — which is also what keeps
+-- effective_status in v_events right with no change to the view.
+-- series_count, when set, stops it after that many meetings,
+-- whichever comes first.
+--
+-- series_frequency:
+--   weekly            on the ticked weekdays, every N weeks
+--   monthly_date      on starts_on's day of the month (the 13th),
+--                     every N months; a short month uses its last day
+--   monthly_weekday   on starts_on's weekday position (2nd Tuesday),
+--                     every N months; a 5th becomes "last"
+--
+-- One boolean per weekday rather than a packed text column: each
+-- is a checkbox the CRUD engine already knows how to validate and
+-- write, and a CHECK can hold it to 0 or 1.
+--
+-- frequency and interval are NOT NULL with defaults so that a box
+-- ticked with nothing else filled in is still a complete schedule —
+-- weekly, on starts_on's weekday — and so every existing row gets
+-- a valid value without a backfill. They are ignored while
+-- is_series is 0.
+--
+-- Times are 'HH:MM', 24-hour, local to the event. The GLOB is a
+-- backstop; the admin engine checks the range before it gets here.
+--
+-- No change to v_events: it is SELECT e.*, so the columns arrive
+-- on /events and /events/:id for free.
+--
+-- No BEGIN...END in this file, so nothing after it is dropped by
+-- the migration runner.
+-- ═══════════════════════════════════════════════════════════════
+
+ALTER TABLE events
+  ADD COLUMN is_series INTEGER NOT NULL DEFAULT 0 CHECK (is_series IN (0, 1));
+
+ALTER TABLE events
+  ADD COLUMN series_frequency TEXT NOT NULL DEFAULT 'weekly'
+    CHECK (series_frequency IN ('weekly', 'monthly_date', 'monthly_weekday'));
+
+ALTER TABLE events
+  ADD COLUMN series_interval INTEGER NOT NULL DEFAULT 1 CHECK (series_interval >= 1);
+
+ALTER TABLE events ADD COLUMN series_sun INTEGER NOT NULL DEFAULT 0 CHECK (series_sun IN (0, 1));
+ALTER TABLE events ADD COLUMN series_mon INTEGER NOT NULL DEFAULT 0 CHECK (series_mon IN (0, 1));
+ALTER TABLE events ADD COLUMN series_tue INTEGER NOT NULL DEFAULT 0 CHECK (series_tue IN (0, 1));
+ALTER TABLE events ADD COLUMN series_wed INTEGER NOT NULL DEFAULT 0 CHECK (series_wed IN (0, 1));
+ALTER TABLE events ADD COLUMN series_thu INTEGER NOT NULL DEFAULT 0 CHECK (series_thu IN (0, 1));
+ALTER TABLE events ADD COLUMN series_fri INTEGER NOT NULL DEFAULT 0 CHECK (series_fri IN (0, 1));
+ALTER TABLE events ADD COLUMN series_sat INTEGER NOT NULL DEFAULT 0 CHECK (series_sat IN (0, 1));
+
+ALTER TABLE events
+  ADD COLUMN series_start_time TEXT
+    CHECK (series_start_time GLOB '[0-2][0-9]:[0-5][0-9]');
+
+ALTER TABLE events
+  ADD COLUMN series_end_time TEXT
+    CHECK (series_end_time GLOB '[0-2][0-9]:[0-5][0-9]');
+
+ALTER TABLE events
+  ADD COLUMN series_count INTEGER CHECK (series_count >= 1);

server/src/routes/content.js

@@ -108,6 +108,25 @@ function shapeHost(row) {
   };
 }
 
+/* The repeating schedule, or null for a one-off. Weekdays collapse
+   from seven flags to a list of the ticked ones, Sunday first; an
+   empty list means "starts_on's weekday", which the client resolves
+   since it already holds starts_on. Occurrences are not sent — they
+   are derived, and the client derives them against its own today. */
+const SERIES_WEEKDAYS = ["sun", "mon", "tue", "wed", "thu", "fri", "sat"];
+
+function shapeSeries(row) {
+  if (!asBool(row.is_series)) return null;
+  return {
+    frequency: row.series_frequency,
+    interval: row.series_interval,
+    weekdays: SERIES_WEEKDAYS.filter((day) => asBool(row[`series_${day}`])),
+    start_time: row.series_start_time,
+    end_time: row.series_end_time,
+    count: row.series_count,
+  };
+}
+
 function shapeEvent(row, links, cardBlocks, hosts = []) {
   const { actions, instagram } = splitLinks(links);
 
@@ -124,6 +143,7 @@ function shapeEvent(row, links, cardBlocks, hosts = []) {
     ends_on: row.ends_on,
     date_label: row.date_label,
     status: row.effective_status,
+    series: shapeSeries(row),
 
     location_label: row.location_label,
     locality: row.locality,