diff --git a/.assets/timeline-gantt.png b/.assets/timeline-gantt.png
index 498ddc0..9b9623e 100644
Binary files a/.assets/timeline-gantt.png and b/.assets/timeline-gantt.png differ
diff --git a/CALENDAR.md b/CALENDAR.md
index ea508cf..5b30cad 100644
--- a/CALENDAR.md
+++ b/CALENDAR.md
@@ -40,8 +40,8 @@ Full untruncated version index.
 |   stable2512-1 | 1.21.1 | 2026-01-26 | 2026-01-26 |  | [Released](https://github.com/paritytech/polkadot-sdk/releases/tag/polkadot-stable2512-1) |
 |   stable2512-2 | 1.21.2 | 2026-02-23 | 2026-02-23 |  | [Released](https://github.com/paritytech/polkadot-sdk/releases/tag/polkadot-stable2512-2) |
 |   stable2512-3 | 1.21.3 | 2026-03-23 | 2026-03-23 |  | [Released](https://github.com/paritytech/polkadot-sdk/releases/tag/polkadot-stable2512-3) |
-|   stable2512-4 | 1.21.4 | 2026-04-20 | 2026-04-23 |  | Planned |
-|   stable2512-5 | 1.21.5 | 2026-05-18 | 2026-05-21 |  | Planned |
+|   stable2512-4 | 1.21.4 | 2026-04-20 | 2026-04-23 |  | ~~Cancelled~~ |
+|   stable2512-5 | 1.21.5 | 2026-05-21 | 2026-05-21 |  | [Released](https://github.com/paritytech/polkadot-sdk/releases/tag/polkadot-stable2512-5) |
 |   stable2512-6 | 1.21.6 | 2026-06-15 | 2026-06-18 |  | Planned |
 |   stable2512-7 | 1.21.7 | 2026-07-20 | 2026-07-23 |  | Planned |
 |   stable2512-8 | 1.21.8 | 2026-08-17 | 2026-08-20 |  | Planned |
diff --git a/README.md b/README.md
index 149d3d9..69415be 100644
--- a/README.md
+++ b/README.md
@@ -31,11 +31,11 @@ Planned and historic release dates:
 |   stable2603-4 | 1.22.4 | 2026-07-27 | 2026-07-30 |  | Planned |
 |   [9 more planned](CALENDAR.md) |  |  | | |
 | **stable2512** | 1.21.0 | 2025-11-17 | 2025-12-22 | 2027-01-01 | [Released](https://github.com/paritytech/polkadot-sdk/releases/tag/polkadot-stable2512) |
-|   stable2512-2 | 1.21.2 | 2026-02-23 | 2026-02-23 |  | [Released](https://github.com/paritytech/polkadot-sdk/releases/tag/polkadot-stable2512-2) |
-|   stable2512-3 | 1.21.3 | 2026-03-23 | 2026-03-23 |  | [Released](https://github.com/paritytech/polkadot-sdk/releases/tag/polkadot-stable2512-3) |
-|   stable2512-4 | 1.21.4 | 2026-04-20 | 2026-04-23 |  | Planned |
-|   stable2512-5 | 1.21.5 | 2026-05-18 | 2026-05-21 |  | Planned |
-|   [1 more past, 7 more planned](CALENDAR.md) |  |  | | |
+|   stable2512-4 | 1.21.4 | 2026-04-20 | 2026-04-23 |  | ~~Cancelled~~ |
+|   stable2512-5 | 1.21.5 | 2026-05-21 | 2026-05-21 |  | [Released](https://github.com/paritytech/polkadot-sdk/releases/tag/polkadot-stable2512-5) |
+|   stable2512-6 | 1.21.6 | 2026-06-15 | 2026-06-18 |  | Planned |
+|   stable2512-7 | 1.21.7 | 2026-07-20 | 2026-07-23 |  | Planned |
+|   [3 more past, 5 more planned](CALENDAR.md) |  |  | | |
 | **stable2509** | 1.20.0 | 2025-08-18 | 2025-10-08 | 2026-10-02 | [Released](https://github.com/paritytech/polkadot-sdk/releases/tag/polkadot-stable2509) |
 |   stable2509-7 | 1.20.7 | 2026-04-13 | 2026-04-16 |  | [Released](https://github.com/paritytech/polkadot-sdk/releases/tag/polkadot-stable2509-7) |
 |   stable2509-8 | 1.20.8 | 2026-05-15 | 2026-05-15 |  | [Released](https://github.com/paritytech/polkadot-sdk/releases/tag/polkadot-stable2509-8) |
diff --git a/releases-v1.ics b/releases-v1.ics
index 35b912a..00f97eb 100644
--- a/releases-v1.ics
+++ b/releases-v1.ics
@@ -1336,29 +1336,29 @@ BEGIN:VEVENT
 SUMMARY:stable2512-4 Cutoff
 DTSTART;VALUE=DATE:20260420
 DTEND;VALUE=DATE:20260421
-DESCRIPTION:Cutoff for stable2512-4 (planned)\n\nFull Calendar: https://gi
+DESCRIPTION:Cutoff for stable2512-4 (skipped)\n\nFull Calendar: https://gi
  thub.com/paritytech/release-registry/blob/main/CALENDAR.md#calendar
 END:VEVENT
 BEGIN:VEVENT
 SUMMARY:stable2512-4 Release
 DTSTART;VALUE=DATE:20260423
 DTEND;VALUE=DATE:20260424
-DESCRIPTION:Release of stable2512-4 (planned)\n\nFull Calendar: https://gi
+DESCRIPTION:Release of stable2512-4 (skipped)\n\nFull Calendar: https://gi
  thub.com/paritytech/release-registry/blob/main/CALENDAR.md#calendar
 END:VEVENT
 BEGIN:VEVENT
 SUMMARY:stable2512-5 Cutoff
-DTSTART;VALUE=DATE:20260518
-DTEND;VALUE=DATE:20260519
-DESCRIPTION:Cutoff for stable2512-5 (planned)\n\nFull Calendar: https://gi
- thub.com/paritytech/release-registry/blob/main/CALENDAR.md#calendar
+DTSTART;VALUE=DATE:20260521
+DTEND;VALUE=DATE:20260522
+DESCRIPTION:Cutoff for stable2512-5 (released)\n\nFull Calendar: https://g
+ ithub.com/paritytech/release-registry/blob/main/CALENDAR.md#calendar
 END:VEVENT
 BEGIN:VEVENT
 SUMMARY:stable2512-5 Release
 DTSTART;VALUE=DATE:20260521
 DTEND;VALUE=DATE:20260522
-DESCRIPTION:Release of stable2512-5 (planned)\n\nFull Calendar: https://gi
- thub.com/paritytech/release-registry/blob/main/CALENDAR.md#calendar
+DESCRIPTION:Release of stable2512-5 (released)\n\nFull Calendar: https://g
+ ithub.com/paritytech/release-registry/blob/main/CALENDAR.md#calendar
 END:VEVENT
 BEGIN:VEVENT
 SUMMARY:stable2512-6 Cutoff
diff --git a/releases-v1.json b/releases-v1.json
index bd039c2..061f912 100644
--- a/releases-v1.json
+++ b/releases-v1.json
@@ -1152,18 +1152,17 @@
             "publish": {
               "estimated": "2026-04-23"
             },
-            "state": "planned",
+            "state": "skipped",
             "semver": "1.21.4"
           },
           {
             "name": "stable2512-5",
-            "cutoff": {
-              "estimated": "2026-05-18"
-            },
+            "cutoff": "2026-05-21",
             "publish": {
-              "estimated": "2026-05-21"
+              "when": "2026-05-21",
+              "tag": "polkadot-stable2512-5"
             },
-            "state": "planned",
+            "state": "released",
             "semver": "1.21.5"
           },
           {