diff --git a/packages/app/src/lib/api-route-catalog.ts b/packages/app/src/lib/api-route-catalog.ts
index bba48de0a..7e23a541e 100644
--- a/packages/app/src/lib/api-route-catalog.ts
+++ b/packages/app/src/lib/api-route-catalog.ts
@@ -404,10 +404,10 @@ export const apiContractSourceDigests = [
   },
   {
     source: '../constants/src/models.ts',
-    // Reviewed for the release-date table move: it adds MODEL_RELEASE_DATES and
-    // getModelReleaseDate. No published model name, alias, or parameter enum is
-    // touched, and no endpoint exposes a release date, so the docs stand.
-    sourceSha256: 'fde7ec056e048452663ddcaa46af137e9ec192676b94c701f57bcc4498417157',
+    // Reviewed again for the release-date corrections: values inside
+    // MODEL_RELEASE_DATES only. No published model name, alias, or parameter enum
+    // is touched, and no endpoint exposes a release date, so the docs stand.
+    sourceSha256: 'f8f46a341bf57384c0080c2ed75d867801142675ded08225281cf7c102236628',
     reviewArea: {
       en: 'Published benchmark and TCO model names, aliases, and parameter enums.',
       zh: '已发布基准与 TCO 模型名称、别名和参数枚举。',
diff --git a/packages/app/src/lib/model-architectures.test.ts b/packages/app/src/lib/model-architectures.test.ts
index 430147c73..6cac00991 100644
--- a/packages/app/src/lib/model-architectures.test.ts
+++ b/packages/app/src/lib/model-architectures.test.ts
@@ -1,7 +1,7 @@
 import { MODEL_RELEASE_DATES, getModelReleaseDate } from '@semianalysisai/inferencex-constants';
 import { describe, expect, it } from 'vitest';
 
-import { Model } from '@/lib/data-mappings';
+import { MODEL_OPTIONS, Model } from '@/lib/data-mappings';
 
 import {
   type SubBlockFlow,
@@ -21,7 +21,35 @@ import {
   MODEL_ARCHITECTURES,
 } from './model-architectures';
 
-describe('MODEL_RELEASE_DATES keys', () => {
+describe('MODEL_RELEASE_DATES coverage', () => {
+  it('has a sourced date for every model the user can select', () => {
+    // Without a date the Fleet Lifecycle axis falls back to the model's first
+    // benchmark run, which reads as "this is when the model appeared" when it is
+    // really "this is when we got to it" — for gpt-oss that gap is five weeks.
+    // A model whose release date genuinely cannot be sourced belongs in an
+    // explicit allowlist here, so the gap stays visible; do not delete the test.
+    const missing = MODEL_OPTIONS.filter((model) => !getModelReleaseDate(model));
+    expect(missing).toEqual([]);
+  });
+
+  it('anchors each model to its weights publication, not its first sweep', () => {
+    // Pinned so a silent revert fails. Every one of these predates the model's
+    // first InferenceX sweep, which is the invariant that caught the four wrong
+    // dates: a model cannot be benchmarked before its weights exist.
+    expect(getModelReleaseDate(Model.Kimi_K3)).toBe('2026-07-27');
+    expect(getModelReleaseDate(Model.GLM_5_2)).toBe('2026-06-13');
+    expect(getModelReleaseDate(Model.MiniMax_M3)).toBe('2026-06-07');
+    expect(getModelReleaseDate(Model.DeepSeek_V4_Pro)).toBe('2026-04-24');
+    expect(getModelReleaseDate(Model.GLM_5)).toBe('2026-02-13');
+    expect(getModelReleaseDate(Model.Qwen3_5)).toBe('2026-02-16');
+    expect(getModelReleaseDate(Model.MiniMax_M2_5)).toBe('2026-02-12');
+    expect(getModelReleaseDate(Model.Kimi_K2_5)).toBe('2026-01-27');
+    expect(getModelReleaseDate(Model.GptOss)).toBe('2025-08-05');
+    expect(getModelReleaseDate(Model.DeepSeek_R1)).toBe('2025-05-28');
+    expect(getModelReleaseDate(Model.Llama3_3_70B)).toBe('2024-12-06');
+    expect(getModelReleaseDate(Model.Llama3_1_70B)).toBe('2024-07-23');
+  });
+
   it('names a real model, so no entry is dead weight', () => {
     // The table is keyed by string because it lives in the constants package,
     // below the `Model` enum. A key that matches no model never throws — the
@@ -72,12 +100,11 @@ describe('MODEL_ARCHITECTURES', () => {
 
   it('sources every architecture caption from the one release-date table', () => {
     // The diagram prints "Released by {developer} on {date}", so an entry with a
-    // developer and no date silently drops the whole caption. Listing the models
-    // that have no sourced date keeps that visible instead of invisible.
+    // developer and no date silently drops the whole caption.
     const missing = Object.values(MODEL_ARCHITECTURES)
       .filter((arch) => arch?.developer && !getModelReleaseDate(arch.model))
       .map((arch) => arch!.model);
-    expect(missing).toEqual([Model.MiniMax_M3]);
+    expect(missing).toEqual([]);
   });
 
   it('ensures dense models have equal active and total params', () => {
diff --git a/packages/constants/src/models.test.ts b/packages/constants/src/models.test.ts
index c251996ac..3f5a87221 100644
--- a/packages/constants/src/models.test.ts
+++ b/packages/constants/src/models.test.ts
@@ -70,8 +70,10 @@ describe('MODEL_RELEASE_DATES', () => {
   });
 
   it('returns null rather than throwing for a model with no sourced date', () => {
-    expect(getModelReleaseDate('GLM-5.2')).toBeNull();
+    // Every model shipped today has a date, so this documents the fallback path
+    // that a future model arrives on rather than an existing gap.
     expect(getModelReleaseDate('not-a-model')).toBeNull();
+    expect(getModelReleaseDate('')).toBeNull();
   });
 });
 
diff --git a/packages/constants/src/models.ts b/packages/constants/src/models.ts
index e3c126ea2..0dd46ea40 100644
--- a/packages/constants/src/models.ts
+++ b/packages/constants/src/models.ts
@@ -105,14 +105,66 @@ export function rowToSequence(row: {
  * earliest date they actually have data for.
  */
 export const MODEL_RELEASE_DATES: Record<string, string> = {
+  // Newest first. `sweep:` is the model's "Date added" from MODELS.md — the first
+  // InferenceX benchmark — recorded so the "cannot predate its own weights"
+  // invariant above is checkable by eye at review time.
+  //
+  // Weights published on Hugging Face 2026-07-27 under the Kimi K3 License,
+  // eleven days after the 2026-07-16 product launch; the gap was to let vLLM,
+  // NVIDIA and AMD prepare day-zero support. sweep: 2026-07-27 — day zero.
+  'Kimi-K3': '2026-07-27',
+  // Zhipu launched GLM-5.2 on 2026-06-13 via the GLM Coding Plan with MIT
+  // weights at zai-org/GLM-5.2; standalone API and provider support followed
+  // over the next few days. One source dates the Hugging Face upload 2026-06-16
+  // instead, so this is ±3 days — immaterial on a multi-month axis, but it is an
+  // announcement-day date rather than a confirmed upload day. sweep: 2026-07-18.
+  'GLM-5.2': '2026-06-13',
+  // Weights and the official MXFP8 quant live on Hugging Face at
+  // MiniMaxAI/MiniMax-M3 by 2026-06-07, under the custom minimax-community
+  // license. The 2026-06-01 launch shipped API access only; the arXiv report
+  // followed on 2026-06-11. sweep: 2026-06-12.
+  'MiniMax-M3': '2026-06-07',
+  // V4 Preview — V4-Pro (1.6T total / 49B active) and V4-Flash (284B/13B)
+  // published together under MIT on Hugging Face, the API and chat.deepseek.com.
+  // V4-Pro-0813 went GA on 2026-08-13, but the Hugging Face repo still hosts the
+  // April preview build, so the weights date is unchanged. sweep: 2026-04-25.
+  'DeepSeek-V4-Pro': '2026-04-24',
+  // Bucket covers GLM-5 and GLM-5.1, so the date is GLM-5's: released
+  // 2026-02-13, 744B/40B active, MIT, trained entirely on Huawei Ascend. Sources
+  // put the weights in "mid-February" without a day, and reporting clusters on
+  // 2026-02-13 and 2026-02-17; the Hugging Face commit history at zai-org/GLM-5
+  // is the authority if this ever needs to be exact. GLM-5.1 followed in April
+  // 2026. sweep: 2026-03-06.
+  'GLM-5': '2026-02-13',
+  // Apache 2.0 weights, plus official FP8 and GPTQ-Int4 quants, published at
+  // Qwen/Qwen3.5-397B-A17B on 2026-02-16 — the same day InferenceX first swept
+  // it. sweep: 2026-02-16 — day zero.
+  'Qwen-3.5-397B-A17B': '2026-02-16',
+  // Bucket covers M2.5 and M2.7, so the date is M2.5's: announced 2026-02-12
+  // with weights on Hugging Face, architecturally unchanged from M2 (230B/10B).
+  // Was 2025-10-25, which is M2's launch, not M2.5's — `model-architectures.ts`
+  // still points its sourceUrl at MiniMax-M2, which is where that came from.
+  // sweep: 2026-02-18.
+  'MiniMax-M2.5': '2026-02-12',
+  // Weights at moonshotai/Kimi-K2.5 on 2026-01-27 under a modified MIT license,
+  // 1.04T total / 32B active. sweep: 2026-02-17.
+  'Kimi-K2.5': '2026-01-27',
+  // Weights landed on Hugging Face 2025-08-05 under Apache 2.0, alongside
+  // gpt-oss-20b — OpenAI's first open-weight release since GPT-2. AWS Bedrock
+  // lists the same launch date; the model-card paper followed on 2025-08-08. Was
+  // 2025-06-13, which precedes the release by seven weeks and matches no
+  // published event. sweep: 2025-09-09.
+  'gpt-oss-120b': '2025-08-05',
+  // Announced by WeChat post and pushed to Hugging Face on 2025-05-28 under MIT
+  // — the date the model name encodes. The model card commit landed a day later,
+  // weights first. sweep: 2025-08-13.
   'DeepSeek-R1-0528': '2025-05-28',
+  // Meta published Llama 3.3 70B Instruct on 2024-12-06. sweep: 2025-08-12,
+  // shipped as workflow templates in the initial repo import.
   'Llama-3.3-70B-Instruct-FP8': '2024-12-06',
+  // Llama 3.1 was published 2024-07-23. Hidden in the model selector, but the
+  // architecture diagram still captions it. No InferenceX sweep of its own.
   'Llama-3.1-70B-Instruct-FP8-KV': '2024-07-23',
-  'gpt-oss-120b': '2025-06-13',
-  'Kimi-K2.5': '2026-01-27',
-  'Kimi-K3': '2026-06-13',
-  'MiniMax-M2.5': '2025-10-25',
-  'DeepSeek-V4-Pro': '2026-06-08',
 };
 
 /** Release date for a display model name, or null when we have no sourced date. */