From 9803431e498ce04ded386bcbd3ac4af5886c6d91 Mon Sep 17 00:00:00 2001
From: Takaaki Abe <me@abnoumaru.com>
Date: Tue, 13 Oct 2026 12:41:21 +0900
Subject: [PATCH] fix(tinybird): reject timezones whose offset is not a whole
 hour in the hourly status pipes

---
 packages/tinybird/src/client.test.ts | 48 ++++++++++++++++++++++++++++
 packages/tinybird/src/client.ts      | 37 ++++++++++++++++++---
 2 files changed, 80 insertions(+), 5 deletions(-)

diff --git a/packages/tinybird/src/client.test.ts b/packages/tinybird/src/client.test.ts
index 17b015f40..826228e0c 100644
--- a/packages/tinybird/src/client.test.ts
+++ b/packages/tinybird/src/client.test.ts
@@ -156,3 +156,51 @@ describe("response-log facet pipes", () => {
     });
   }
 });
+
+const status60mGetters = [
+  "httpStatus60m",
+  "tcpStatus60m",
+  "dnsStatus60m",
+  "icmpStatus60m",
+  "grpcStatus60m",
+] as const;
+
+describe("hourly status pipes", () => {
+  const tb = new OSTinybird({ token: "a-token" });
+
+  for (const name of status60mGetters) {
+    for (const timezone of [
+      "Asia/Kolkata",
+      "Asia/Kathmandu",
+      "Australia/Lord_Howe",
+      "Mars/Olympus",
+    ]) {
+      test(`${name} rejects ${timezone}, whose days don't start on a UTC hour`, async () => {
+        await expect(
+          tb[name]({ monitorIds: ["1"], timezone }),
+        ).rejects.toThrow();
+      });
+    }
+
+    test(`${name} accepts whole-hour timezones, with or without DST`, async () => {
+      for (const timezone of [
+        "UTC",
+        "Asia/Tokyo",
+        "Europe/Berlin",
+        "America/New_York",
+      ]) {
+        expect(await tb[name]({ monitorIds: ["1"], timezone })).toEqual({
+          meta: [],
+          data: [],
+        });
+      }
+    });
+
+    test(`${name} defaults to UTC`, async () => {
+      expect(await tb[name]({ monitorIds: ["1"] })).toEqual({
+        meta: [],
+        data: [],
+      });
+    });
+  }
+});
diff --git a/packages/tinybird/src/client.ts b/packages/tinybird/src/client.ts
index be2918e14..c74c27d29 100644
--- a/packages/tinybird/src/client.ts
+++ b/packages/tinybird/src/client.ts
@@ -14,6 +14,33 @@ const PUBLIC_CACHE = 300; // 5 * 60 = 300s = 5m
 const DEV_CACHE = 10 * 60; // 10m
 const REVALIDATE = env.NODE_ENV === "development" ? DEV_CACHE : 0;
 
+// The 60m pipes group UTC-hour buckets into local days, which only lines up
+// when every offset the zone uses is a whole number of hours. January and
+// July cover both sides of DST.
+function isWholeHourTimeZone(timeZone: string): boolean {
+  let format: Intl.DateTimeFormat;
+  try {
+    format = new Intl.DateTimeFormat("en-US", {
+      timeZone,
+      timeZoneName: "longOffset",
+    });
+  } catch (error) {
+    if (error instanceof RangeError) return false;
+    throw error;
+  }
+  const year = new Date().getUTCFullYear();
+  return [0, 6].every((month) => {
+    const offset = format
+      .formatToParts(new Date(Date.UTC(year, month, 1)))
+      .find((p) => p.type === "timeZoneName")?.value;
+    return offset === "GMT" || /^GMT[+-]\d{2}:00$/.test(offset ?? "");
+  });
+}
+
+const wholeHourTimeZone = z
+  .string()
+  .refine(isWholeHourTimeZone, "timezone offset must be a whole hour");
+
 // Daily-aggregate columns shared by the external-status history pipes (page-
 // level and per-component). One shape so the `day` GMT-parse can't drift.
 const externalStatusHistoryDailyShape = {
@@ -817,7 +844,7 @@ export class OSTinybird {
       pipe: "endpoint__http_status_60m__v0",
       parameters: z.object({
         monitorIds: z.string().array(),
-        timezone: z.string().prefault("UTC"),
+        timezone: wholeHourTimeZone.prefault("UTC"),
       }),
       data: z.object({
         day: z.number().transform((ms) => new Date(ms).toISOString()),
@@ -1403,7 +1430,7 @@ export class OSTinybird {
       pipe: "endpoint__tcp_status_60m__v0",
       parameters: z.object({
         monitorIds: z.string().array(),
-        timezone: z.string().prefault("UTC"),
+        timezone: wholeHourTimeZone.prefault("UTC"),
       }),
       data: z.object({
         day: z.number().transform((ms) => new Date(ms).toISOString()),
@@ -1822,7 +1849,7 @@ export class OSTinybird {
       pipe: "endpoint__icmp_status_60m__v0",
       parameters: z.object({
         monitorIds: z.string().array(),
-        timezone: z.string().prefault("UTC"),
+        timezone: wholeHourTimeZone.prefault("UTC"),
       }),
       data: z.object({
         day: z.number().transform((ms) => new Date(ms).toISOString()),
@@ -2312,7 +2339,7 @@ export class OSTinybird {
       pipe: "endpoint__grpc_status_60m__v0",
       parameters: z.object({
         monitorIds: z.string().array(),
-        timezone: z.string().prefault("UTC"),
+        timezone: wholeHourTimeZone.prefault("UTC"),
       }),
       data: z.object({
         day: z.number().transform((ms) => new Date(ms).toISOString()),
@@ -3617,7 +3644,7 @@ export class OSTinybird {
       pipe: "endpoint__dns_status_60m__v0",
       parameters: z.object({
         monitorIds: z.string().array(),
-        timezone: z.string().prefault("UTC"),
+        timezone: wholeHourTimeZone.prefault("UTC"),
       }),
       data: z.object({
         day: z.number().transform((ms) => new Date(ms).toISOString()),
-- 
2.51.2