Dated the demo cons in the Persistence package from the weekend after seeding, and re-dated the ones already seeded.

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

Packages/Persistence/Sources/Internal/Migrations/CreateCommunity.swift

@@ -29,7 +29,7 @@ struct CreateCommunity: AsyncMigration {
             .unique(on: "user_id", "series_slug", "issue")
             .create()
 
-        for (event, shops) in Seed.events {
+        for (event, shops) in Seed.events(after: .init()) {
             let record = EventRecord(event)
 
             try await record.save(on: database)

Packages/Persistence/Sources/Internal/Migrations/RedateEvents.swift

@@ -0,0 +1,21 @@
+import FluentKit
+import Foundation
+
+/// Re-dates the demo cons from the first weekend after it runs, for databases seeded when ``CreateCommunity`` used fixed dates.
+struct RedateEvents: AsyncMigration {
+
+    // MARK: Methods
+
+    func prepare(on database: Database) async throws {
+        for (event, _) in Seed.events(after: .init()) {
+            try await EventRecord.query(on: database)
+                .filter(\.$slug == event.slug)
+                .set(\.$startsOn, to: event.startsOn)
+                .set(\.$endsOn, to: event.endsOn)
+                .update()
+        }
+    }
+
+    func revert(on database: Database) async throws {}
+
+}

Packages/Persistence/Sources/Internal/Seeds/Seed.swift

@@ -158,29 +158,36 @@ enum Seed {
         ),
     ]
 
-    /// The demo cons, soonest first, each with the slugs of the shops trading there.
-    static let events: [(event: Event, shops: [String])] = [
-        (.init(slug: "dutch-comic-con", name: "Dutch Comic Con", venue: "Jaarbeurs, Utrecht", startsOn: day(2026, 9, 26), endsOn: day(2026, 9, 27)),
-         ["kestrel-row-comics", "silverfish-comics", "third-panel-supply"]),
-        (.init(slug: "stripdagen-haarlem", name: "Stripdagen Haarlem", venue: "Grote Markt, Haarlem", startsOn: day(2026, 10, 3), endsOn: day(2026, 10, 4)),
-         ["silverfish-comics"]),
-        (.init(slug: "comic-con-amsterdam", name: "Comic Con Amsterdam", venue: "RAI, Amsterdam", startsOn: day(2026, 11, 21), endsOn: day(2026, 11, 22)),
-         ["kestrel-row-comics", "inkwell-and-staple"]),
-        (.init(slug: "comic-con-brussels", name: "Comic Con Brussels", venue: "Tour & Taxis, Brussels", startsOn: day(2026, 12, 5), endsOn: day(2026, 12, 6)),
-         ["third-panel-supply"]),
-    ]
+    /// The demo cons, soonest first, each with the slugs of the shops trading there, dated from the first weekend after `date`.
+    static func events(
+        after date: Date
+    ) -> [(event: Event, shops: [String])] {
+        [
+            ("dutch-comic-con", "Dutch Comic Con", "Jaarbeurs, Utrecht", 0, ["kestrel-row-comics", "silverfish-comics", "third-panel-supply"]),
+            ("stripdagen-haarlem", "Stripdagen Haarlem", "Grote Markt, Haarlem", 1, ["silverfish-comics"]),
+            ("comic-con-amsterdam", "Comic Con Amsterdam", "RAI, Amsterdam", 8, ["kestrel-row-comics", "inkwell-and-staple"]),
+            ("comic-con-brussels", "Comic Con Brussels", "Tour & Taxis, Brussels", 10, ["third-panel-supply"]),
+        ]
+        .map { slug, name, venue, week, shops in
+            let (startsOn, endsOn) = weekend(week, after: date)
 
-    /// Noon on a day in Amsterdam, where the demo cons are dated.
-    static func day(
-        _ year: Int,
-        _ month: Int,
-        _ day: Int
-    ) -> Date {
+            return (.init(slug: slug, name: name, venue: venue, startsOn: startsOn, endsOn: endsOn), shops)
+        }
+    }
+
+    /// Noon on the Saturday and Sunday `week` weeks on from the first weekend after `date`, in Amsterdam, where the demo cons are held.
+    static func weekend(
+        _ week: Int,
+        after date: Date
+    ) -> (startsOn: Date, endsOn: Date) {
         var calendar = Calendar(identifier: .gregorian)
 
         calendar.timeZone = TimeZone(identifier: "Europe/Amsterdam") ?? .gmt
 
-        return calendar.date(from: .init(year: year, month: month, day: day, hour: 12)) ?? .distantPast
+        let saturday = calendar.nextDate(after: date, matching: .init(hour: 12, weekday: 7), matchingPolicy: .nextTime) ?? date
+        let startsOn = calendar.date(byAdding: .weekOfYear, value: week, to: saturday) ?? saturday
+
+        return (startsOn, calendar.date(byAdding: .day, value: 1, to: startsOn) ?? startsOn)
     }
 
     /// The runs the demo listings belong to.

Packages/Persistence/Sources/Public/Methods/PrepareDB.swift

@@ -33,6 +33,7 @@ public struct PrepareDB: Sendable {
             CreatePasskey(),
             CreateCollecting(),
             CreateCommunity(),
+            RedateEvents(),
         ])
     }
 

Packages/Persistence/Tests/Cases/Public/Repositories/CommunityRepositoryTests.swift

@@ -46,13 +46,13 @@ struct CommunityRepositoryTests {
             let clock = Clock()
             let collecting = CollectingRepository(fluent: fluent, now: clock.now)
 
-            // 22 September 2026: every demo con is still to come.
-            clock.advance(by: Seed.day(2026, 9, 22).timeIntervalSince(clock.now()))
+            // The present, which every demo con is seeded after.
+            clock.advance(by: Date().timeIntervalSince(clock.now()))
 
             let all = try await collecting.upcomingEvents()
 
-            // Sunday 27 September, the con's last day: still on. Two weeks later it is over, and so is Stripdagen.
-            clock.advance(by: 5 * 86_400)
+            // The first con's last day: still on. Two weeks later it is over, and so is Stripdagen.
+            clock.advance(by: try #require(all.first).endsOn.timeIntervalSince(clock.now()))
 
             let lastDay = try await collecting.upcomingEvents()
 
@@ -67,17 +67,35 @@ struct CommunityRepositoryTests {
         }
     }
 
+    @Test
+    func `dates the demo cons on weekends, from the first one after seeding`() {
+        var calendar = Calendar(identifier: .gregorian)
+
+        calendar.timeZone = TimeZone(identifier: "Europe/Amsterdam") ?? .gmt
+
+        // Monday 21 September 2026: the dates the prototype first shipped with.
+        let days = Seed.events(after: Date(timeIntervalSince1970: 1_790_000_000)).map { entry in
+            [entry.event.startsOn, entry.event.endsOn]
+                .map { calendar.dateComponents([.month, .day, .hour], from: $0) }
+                .map { "\($0.month ?? 0)/\($0.day ?? 0) \($0.hour ?? 0):00" }
+        }
+
+        #expect(days == [
+            ["9/26 12:00", "9/27 12:00"],
+            ["10/3 12:00", "10/4 12:00"],
+            ["11/21 12:00", "11/22 12:00"],
+            ["12/5 12:00", "12/6 12:00"],
+        ])
+    }
+
     @Test
     func `lets a seller pick the events their shop trades at`() async throws {
         try await withDatabase { fluent in
-            let clock = Clock()
-            let collecting = CollectingRepository(fluent: fluent, now: clock.now)
+            let collecting = CollectingRepository(fluent: fluent)
             let accounts = AccountRepository(fluent: fluent)
             let joost = try await accounts.account(email: "joost@kestrelrow.example")
             let mara = try await accounts.account(email: "mara.v@example.com")
 
-            clock.advance(by: Seed.day(2026, 9, 22).timeIntervalSince(clock.now()))
-
             try await collecting.setEvents(["stripdagen-haarlem", "comic-con-amsterdam", "no-such-event"], forShopOwnedBy: joost)
             // An account without a shop changes nothing.
             try await collecting.setEvents(["dutch-comic-con"], forShopOwnedBy: mara)