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/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)