diff --git a/hindsight-api/hindsight_api/api/http.py b/hindsight-api/hindsight_api/api/http.py
index eef3a1d7..df900f4b 100644
--- a/hindsight-api/hindsight_api/api/http.py
+++ b/hindsight-api/hindsight_api/api/http.py
@@ -29,7 +29,7 @@ def _parse_metadata(metadata: Any) -> dict[str, Any]:
     return {}
 
 
-from pydantic import BaseModel, ConfigDict, Field
+from pydantic import BaseModel, ConfigDict, Field, field_validator
 
 from hindsight_api import MemoryEngine
 from hindsight_api.engine.db_utils import acquire_with_retry
@@ -291,7 +291,7 @@ class MemoryItem(BaseModel):
                 "metadata": {"source": "slack", "channel": "engineering"},
                 "document_id": "meeting_notes_2024_01_15",
             }
-        }
+        },
     )
 
     content: str
@@ -300,6 +300,23 @@ class MemoryItem(BaseModel):
     metadata: dict[str, str] | None = None
     document_id: str | None = Field(default=None, description="Optional document ID for this memory item.")
 
+    @field_validator("timestamp", mode="before")
+    @classmethod
+    def validate_timestamp(cls, v):
+        if v is None or v == "":
+            return None
+        if isinstance(v, datetime):
+            return v
+        if isinstance(v, str):
+            try:
+                # Try parsing as ISO format
+                return datetime.fromisoformat(v.replace("Z", "+00:00"))
+            except ValueError as e:
+                raise ValueError(
+                    f"Invalid timestamp/event_date format: '{v}'. Expected ISO format like '2024-01-15T10:30:00' or '2024-01-15T10:30:00Z'"
+                ) from e
+        raise ValueError(f"timestamp must be a string or datetime, got {type(v).__name__}")
+
 
 class RetainRequest(BaseModel):
     """Request model for retain endpoint."""
diff --git a/hindsight-control-plane/src/components/add-memory-view.tsx b/hindsight-control-plane/src/components/add-memory-view.tsx
index f28d3b5a..3f26bced 100644
--- a/hindsight-control-plane/src/components/add-memory-view.tsx
+++ b/hindsight-control-plane/src/components/add-memory-view.tsx
@@ -39,7 +39,8 @@ export function AddMemoryView() {
     try {
       const item: any = { content };
       if (context) item.context = context;
-      if (eventDate) item.timestamp = eventDate;
+      // datetime-local gives "2024-01-15T10:30", add seconds for proper ISO format
+      if (eventDate) item.timestamp = eventDate + ":00";
 
       const data: any = await client.retain({
         bank_id: currentBank,
diff --git a/hindsight-control-plane/src/components/bank-selector.tsx b/hindsight-control-plane/src/components/bank-selector.tsx
index 9eb3cc36..76e6d255 100644
--- a/hindsight-control-plane/src/components/bank-selector.tsx
+++ b/hindsight-control-plane/src/components/bank-selector.tsx
@@ -85,7 +85,8 @@ function BankSelectorInner() {
     try {
       const item: any = { content: docContent };
       if (docContext) item.context = docContext;
-      if (docEventDate) item.event_date = docEventDate;
+      // datetime-local gives "2024-01-15T10:30", add seconds for proper ISO format
+      if (docEventDate) item.timestamp = docEventDate + ":00";
 
       const params: any = {
         bank_id: currentBank,
diff --git a/package-lock.json b/package-lock.json
index bd0be49d..1d3ded2e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -24202,6 +24202,111 @@
         "type": "github",
         "url": "https://github.com/sponsors/wooorm"
       }
+    },
+    "node_modules/@next/swc-darwin-x64": {
+      "version": "16.0.10",
+      "resolved": "https://registry.npmjs.org/@next/swc-darwin-x64/-/swc-darwin-x64-16.0.10.tgz",
+      "integrity": "sha512-spbEObMvRKkQ3CkYVOME+ocPDFo5UqHb8EMTS78/0mQ+O1nqE8toHJVioZo4TvebATxgA8XMTHHrScPrn68OGw==",
+      "cpu": [
+        "x64"
+      ],
+      "optional": true,
+      "os": [
+        "darwin"
+      ],
+      "engines": {
+        "node": ">= 10"
+      }
+    },
+    "node_modules/@next/swc-linux-arm64-gnu": {
+      "version": "16.0.10",
+      "resolved": "https://registry.npmjs.org/@next/swc-linux-arm64-gnu/-/swc-linux-arm64-gnu-16.0.10.tgz",
+      "integrity": "sha512-uQtWE3X0iGB8apTIskOMi2w/MKONrPOUCi5yLO+v3O8Mb5c7K4Q5KD1jvTpTF5gJKa3VH/ijKjKUq9O9UhwOYw==",
+      "cpu": [
+        "arm64"
+      ],
+      "optional": true,
+      "os": [
+        "linux"
+      ],
+      "engines": {
+        "node": ">= 10"
+      }
+    },
+    "node_modules/@next/swc-linux-arm64-musl": {
+      "version": "16.0.10",
+      "resolved": "https://registry.npmjs.org/@next/swc-linux-arm64-musl/-/swc-linux-arm64-musl-16.0.10.tgz",
+      "integrity": "sha512-llA+hiDTrYvyWI21Z0L1GiXwjQaanPVQQwru5peOgtooeJ8qx3tlqRV2P7uH2pKQaUfHxI/WVarvI5oYgGxaTw==",
+      "cpu": [
+        "arm64"
+      ],
+      "optional": true,
+      "os": [
+        "linux"
+      ],
+      "engines": {
+        "node": ">= 10"
+      }
+    },
+    "node_modules/@next/swc-linux-x64-gnu": {
+      "version": "16.0.10",
+      "resolved": "https://registry.npmjs.org/@next/swc-linux-x64-gnu/-/swc-linux-x64-gnu-16.0.10.tgz",
+      "integrity": "sha512-AK2q5H0+a9nsXbeZ3FZdMtbtu9jxW4R/NgzZ6+lrTm3d6Zb7jYrWcgjcpM1k8uuqlSy4xIyPR2YiuUr+wXsavA==",
+      "cpu": [
+        "x64"
+      ],
+      "optional": true,
+      "os": [
+        "linux"
+      ],
+      "engines": {
+        "node": ">= 10"
+      }
+    },
+    "node_modules/@next/swc-linux-x64-musl": {
+      "version": "16.0.10",
+      "resolved": "https://registry.npmjs.org/@next/swc-linux-x64-musl/-/swc-linux-x64-musl-16.0.10.tgz",
+      "integrity": "sha512-1TDG9PDKivNw5550S111gsO4RGennLVl9cipPhtkXIFVwo31YZ73nEbLjNC8qG3SgTz/QZyYyaFYMeY4BKZR/g==",
+      "cpu": [
+        "x64"
+      ],
+      "optional": true,
+      "os": [
+        "linux"
+      ],
+      "engines": {
+        "node": ">= 10"
+      }
+    },
+    "node_modules/@next/swc-win32-arm64-msvc": {
+      "version": "16.0.10",
+      "resolved": "https://registry.npmjs.org/@next/swc-win32-arm64-msvc/-/swc-win32-arm64-msvc-16.0.10.tgz",
+      "integrity": "sha512-aEZIS4Hh32xdJQbHz121pyuVZniSNoqDVx1yIr2hy+ZwJGipeqnMZBJHyMxv2tiuAXGx6/xpTcQJ6btIiBjgmg==",
+      "cpu": [
+        "arm64"
+      ],
+      "optional": true,
+      "os": [
+        "win32"
+      ],
+      "engines": {
+        "node": ">= 10"
+      }
+    },
+    "node_modules/@next/swc-win32-x64-msvc": {
+      "version": "16.0.10",
+      "resolved": "https://registry.npmjs.org/@next/swc-win32-x64-msvc/-/swc-win32-x64-msvc-16.0.10.tgz",
+      "integrity": "sha512-E+njfCoFLb01RAFEnGZn6ERoOqhK1Gl3Lfz1Kjnj0Ulfu7oJbuMyvBKNj/bw8XZnenHDASlygTjZICQW+rYW1Q==",
+      "cpu": [
+        "x64"
+      ],
+      "optional": true,
+      "os": [
+        "win32"
+      ],
+      "engines": {
+        "node": ">= 10"
+      }
     }
   }
 }