diff --git a/extensions/slack/src/interactive-replies.test.ts b/extensions/slack/src/interactive-replies.test.ts
index aac2c460d869..decd5fb34aa2 100644
--- a/extensions/slack/src/interactive-replies.test.ts
+++ b/extensions/slack/src/interactive-replies.test.ts
@@ -94,4 +94,101 @@ describe("compileSlackInteractiveReplies", () => {
     );
     expect(result.interactive).toBeUndefined();
   });
+
+  it("keeps time-style colons in Slack button labels", () => {
+    const result = compileSlackInteractiveReplies({
+      text: "[[slack_buttons: Fr 10.07. 9:00:slot_fr_0900, Mo 13.07. 10:45:slot_mo_1045, Today 11:30:ticket:123, Mon 14:30-16:00:slot_range]]",
+    });
+
+    expect(result.interactive).toEqual({
+      blocks: [
+        {
+          type: "buttons",
+          buttons: [
+            { label: "Fr 10.07. 9:00", value: "slot_fr_0900" },
+            { label: "Mo 13.07. 10:45", value: "slot_mo_1045" },
+            { label: "Today 11:30", value: "ticket:123" },
+            { label: "Mon 14:30-16:00", value: "slot_range" },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("keeps button style suffixes after time-style labels", () => {
+    const result = compileSlackInteractiveReplies({
+      text: "[[slack_buttons: Fr 10.07. 9:00:slot_fr_0900:primary, Later 10:45:slot_later:danger]]",
+    });
+
+    expect(result.interactive).toEqual({
+      blocks: [
+        {
+          type: "buttons",
+          buttons: [
+            { label: "Fr 10.07. 9:00", value: "slot_fr_0900", style: "primary" },
+            { label: "Later 10:45", value: "slot_later", style: "danger" },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("preserves colon-containing Slack callback values", () => {
+    const result = compileSlackInteractiveReplies({
+      text: "[[slack_buttons: Model v2:01:open, Step 2:30-day:open, Timed:ticket:9:00:id, Today 11:30:12:34:id, Deny:/approve plugin:approval-123 deny]]",
+    });
+
+    expect(result.interactive).toEqual({
+      blocks: [
+        {
+          type: "buttons",
+          buttons: [
+            { label: "Model v2", value: "01:open" },
+            { label: "Step 2", value: "30-day:open" },
+            { label: "Timed", value: "ticket:9:00:id" },
+            { label: "Today 11:30", value: "12:34:id" },
+            { label: "Deny", value: "/approve plugin:approval-123 deny" },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("keeps single-colon button entries unchanged when the value matches a style name", () => {
+    const result = compileSlackInteractiveReplies({
+      text: "[[slack_buttons: Primary:primary, Danger:danger, Fr 10.07. 9:00:primary]]",
+    });
+
+    expect(result.interactive).toEqual({
+      blocks: [
+        {
+          type: "buttons",
+          buttons: [
+            { label: "Primary", value: "primary" },
+            { label: "Danger", value: "danger" },
+            { label: "Fr 10.07. 9:00", value: "primary" },
+          ],
+        },
+      ],
+    });
+  });
+
+  it("keeps time-style colons in Slack select option labels", () => {
+    const result = compileSlackInteractiveReplies({
+      text: "[[slack_select: Pick a time | Fr 10.07. 9:00:slot_fr_0900, Mo 13.07. 10:45:slot_mo_1045]]",
+    });
+
+    expect(result.interactive).toEqual({
+      blocks: [
+        {
+          type: "select",
+          placeholder: "Pick a time",
+          options: [
+            { label: "Fr 10.07. 9:00", value: "slot_fr_0900" },
+            { label: "Mo 13.07. 10:45", value: "slot_mo_1045" },
+          ],
+        },
+      ],
+    });
+  });
 });
diff --git a/extensions/slack/src/interactive-replies.ts b/extensions/slack/src/interactive-replies.ts
index 06f9ac6c26ac..c4359fdf9842 100644
--- a/extensions/slack/src/interactive-replies.ts
+++ b/extensions/slack/src/interactive-replies.ts
@@ -21,12 +21,36 @@ type SlackChoice = {
   style?: "primary" | "secondary" | "success" | "danger";
 };
 
+function resolveChoiceDelimiter(value: string): number {
+  const firstDelimiter = value.indexOf(":");
+  if (firstDelimiter === -1) {
+    return -1;
+  }
+  const prefix = value.slice(0, firstDelimiter);
+  const suffix = value.slice(firstDelimiter + 1);
+  const startsWithClockLabel = /\b(?:[01]?\d|2[0-3])$/.test(prefix) && /^[0-5]\d/.test(suffix);
+  if (!startsWithClockLabel) {
+    return firstDelimiter;
+  }
+
+  // Legacy syntax makes label and callback colons ambiguous. Recognize only a
+  // complete clock or dash-separated range followed by the real separator/end.
+  const clockEnd = firstDelimiter + 3;
+  const labelSuffix =
+    value.slice(clockEnd).match(/^(?:\s*[-–—]\s*(?:[01]?\d|2[0-3]):[0-5]\d)*\s*/)?.[0] ?? "";
+  const delimiter = clockEnd + labelSuffix.length;
+  if (value[delimiter] === ":") {
+    return delimiter;
+  }
+  return delimiter === value.length ? -1 : firstDelimiter;
+}
+
 function parseChoice(raw: string, options?: { allowStyle?: boolean }): SlackChoice | null {
   const trimmed = raw.trim();
   if (!trimmed) {
     return null;
   }
-  const delimiter = trimmed.indexOf(":");
+  const delimiter = resolveChoiceDelimiter(trimmed);
   if (delimiter === -1) {
     return {
       label: trimmed,