sql(mysql): decode DATETIME/TIMESTAMP as UTC

src/sql/mysql/MySQLTypes.zig

@@ -514,6 +514,68 @@
             return fromBinary(data.slice());
         }
 
+        /// Parse MySQL's text-protocol DATE/DATETIME/TIMESTAMP representation:
+        ///   "YYYY-MM-DD"
+        ///   "YYYY-MM-DD HH:MM:SS"
+        ///   "YYYY-MM-DD HH:MM:SS.ffffff" (1-6 fractional digits)
+        ///
+        /// MySQL TIMESTAMP values are returned in the server's session TZ; DATETIME
+        /// is a naive wall-clock. Both are returned without a TZ designator, and
+        /// Bun interprets them as UTC components so the resulting JS `Date`
+        /// round-trips the bytes the server sent, regardless of the client TZ.
+        pub fn fromText(text: []const u8) !DateTime {
+            if (text.len < 10) return error.InvalidDateTimeText;
+
+            const year = std.fmt.parseInt(u16, text[0..4], 10) catch return error.InvalidDateTimeText;
+            if (text[4] != '-') return error.InvalidDateTimeText;
+            const month = std.fmt.parseInt(u8, text[5..7], 10) catch return error.InvalidDateTimeText;
+            if (text[7] != '-') return error.InvalidDateTimeText;
+            const day = std.fmt.parseInt(u8, text[8..10], 10) catch return error.InvalidDateTimeText;
+
+            // Reject MySQL zero-date sentinels like "0000-00-00" and impossible
+            // calendar values (e.g. 2024-02-31) so the caller produces NaN,
+            // matching the behaviour of the pre-existing JS-parser path.
+            // Otherwise JSC's GregorianDateTime would silently normalize them
+            // into bogus timestamps instead of an Invalid Date.
+            if (month < 1 or month > 12) return error.InvalidDateTimeText;
+            if (day < 1 or day > daysInMonth(year, month)) return error.InvalidDateTimeText;
+
+            var result: DateTime = .{ .year = year, .month = month, .day = day };
+            if (text.len == 10) return result;
+
+            // Either "YYYY-MM-DD HH:MM:SS" or "YYYY-MM-DDTHH:MM:SS" (ISO-style).
+            if (text.len < 19 or (text[10] != ' ' and text[10] != 'T')) return error.InvalidDateTimeText;
+
+            result.hour = std.fmt.parseInt(u8, text[11..13], 10) catch return error.InvalidDateTimeText;
+            if (text[13] != ':') return error.InvalidDateTimeText;
+            result.minute = std.fmt.parseInt(u8, text[14..16], 10) catch return error.InvalidDateTimeText;
+            if (text[16] != ':') return error.InvalidDateTimeText;
+            result.second = std.fmt.parseInt(u8, text[17..19], 10) catch return error.InvalidDateTimeText;
+            // Same rationale as the date checks above. MySQL's strict modes
+            // reject these values, but permissive modes will happily store
+            // them.
+            if (result.hour > 23 or result.minute > 59 or result.second > 59) {
+                return error.InvalidDateTimeText;
+            }
+
+            if (text.len == 19) return result;
+            if (text[19] != '.') return error.InvalidDateTimeText;
+
+            // Fractional seconds: up to 6 digits, right-padded to microseconds.
+            const frac = text[20..];
+            if (frac.len == 0 or frac.len > 6) return error.InvalidDateTimeText;
+            var micro: u32 = 0;
+            for (frac) |c| {
+                if (c < '0' or c > '9') return error.InvalidDateTimeText;
+                micro = micro * 10 + (c - '0');
+            }
+            var pad: usize = 6 - frac.len;
+            while (pad > 0) : (pad -= 1) micro *= 10;
+            result.microsecond = micro;
+
+            return result;
+        }
+
         pub fn fromBinary(val: []const u8) DateTime {
             switch (val.len) {
                 4 => {
@@ -598,13 +660,17 @@
                 },
                 else => return 0,
             }
         }
 
         pub fn toJSTimestamp(this: *const DateTime, globalObject: *JSC.JSGlobalObject) bun.JSError!f64 {
-            return globalObject.gregorianDateTimeToMS(
+            // MySQL's binary DATETIME/TIMESTAMP protocol encodes raw
+            // year/month/day/hour/minute/second/microsecond components with no
+            // timezone information. Interpret them as UTC so the resulting JS
+            // `Date` has the correct UTC epoch regardless of the process TZ.
+            return globalObject.gregorianDateTimeToMSUTC(
                 this.year,
                 this.month,
                 this.day,
                 this.hour,
                 this.minute,
                 this.second,
@@ -635,8 +701,8 @@
             };
         }
 
-        pub fn toJS(this: DateTime, globalObject: *JSC.JSGlobalObject) JSValue {
-            return JSValue.fromDateNumber(globalObject, this.toJSTimestamp());
+        pub fn toJS(this: DateTime, globalObject: *JSC.JSGlobalObject) bun.JSError!JSValue {
+            return JSValue.fromDateNumber(globalObject, try this.toJSTimestamp(globalObject));
         }
 
         pub fn fromJS(value: JSValue, globalObject: *JSC.JSGlobalObject) !DateTime {

src/sql/mysql/protocol/DecodeBinaryValue.zig

@@ -125,10 +125,14 @@
         },
         .MYSQL_TYPE_DATE, .MYSQL_TYPE_TIMESTAMP, .MYSQL_TYPE_DATETIME => switch (try reader.byte()) {
             0 => {
-                return SQLDataCell{ .tag = .date, .value = .{ .date = 0 } };
+                // MySQL's binary protocol sends a zero-length payload for
+                // zero-date sentinels like '0000-00-00'. Return NaN so the
+                // JS side sees an Invalid Date, matching the text-protocol
+                // path instead of surfacing the epoch (1970-01-01T00:00:00Z).
+                return SQLDataCell{ .tag = .date, .value = .{ .date = std.math.nan(f64) } };
             },
             11, 7, 4 => |l| {
                 var data = try reader.read(l);
                 defer data.deinit();
                 const time = try DateTime.fromData(&data);
                 return SQLDataCell{ .tag = .date, .value = .{ .date = try time.toJSTimestamp(globalObject) } };

src/sql/mysql/protocol/ResultSet.zig

@@ -120,10 +120,15 @@ pub const Row = struct {
                 cell.* = SQLDataCell{ .tag = .string, .value = .{ .string = if (slice.len > 0) bun.String.cloneUTF8(slice).value.WTFStringImpl else null }, .free_value = 1 };
             },
             .MYSQL_TYPE_DATE, .MYSQL_TYPE_DATETIME, .MYSQL_TYPE_TIMESTAMP => {
-                var str = bun.String.init(value.slice());
-                defer str.deref();
+                // MySQL text protocol returns naive "YYYY-MM-DD[ HH:MM:SS[.ffffff]]"
+                // values with no timezone designator. Parse the components ourselves
+                // and interpret them as UTC, matching the binary-protocol path. Using
+                // the generic JS date parser would treat them as local time and shift
+                // the result by the client's UTC offset (issue #29208).
+                const slice = value.slice();
                 const date = brk: {
-                    break :brk str.parseDate(this.globalObject) catch |err| {
+                    const dt = DateTime.fromText(slice) catch break :brk std.math.nan(f64);
+                    break :brk dt.toJSTimestamp(this.globalObject) catch |err| {
                         _ = this.globalObject.takeException(err);
                         break :brk std.math.nan(f64);
                     };
@@ -265,6 +270,7 @@ const Data = @import("../../shared/Data.zig").Data;
 const SQLDataCell = @import("../../shared/SQLDataCell.zig").SQLDataCell;
 const SQLQueryResultMode = @import("../../shared/SQLQueryResultMode.zig").SQLQueryResultMode;
 const decodeLengthInt = @import("./EncodeInt.zig").decodeLengthInt;
+const DateTime = @import("../MySQLTypes.zig").Value.DateTime;
 
 const DecodeBinaryValue = @import("./DecodeBinaryValue.zig");
 const decodeBinaryValue = DecodeBinaryValue.decodeBinaryValue;

test/regression/issue/29208.test.ts

@@ -0,0 +1,127 @@
+// https://github.com/oven-sh/bun/issues/29208
+//
+// MySQL DATETIME/TIMESTAMP values were deserialized through JSC's local-time
+// constructor, so on any machine whose process TZ was not UTC the returned
+// JS `Date` was off by the client's UTC offset. `bun test` forces
+// TZ=Etc/UTC on the test runner, which masks the bug, so we set
+// process.env.TZ before decoding and round-trip both DATETIME and TIMESTAMP
+// via the binary (prepared) and text (simple) protocols.
+
+import { SQL, randomUUIDv7 } from "bun";
+import { beforeAll, describe, expect, test } from "bun:test";
+import { describeWithContainer, isDockerEnabled } from "harness";
+
+const EXPECTED_ISO = "2024-01-15T05:30:45.678Z" as const;
+
+async function runRoundTrip(url: string) {
+  // Apply the non-UTC TZ *before* any Date is constructed or SQL query is
+  // decoded — JSC's date cache reads $TZ lazily on its first use.
+  const savedTz = process.env.TZ;
+  process.env.TZ = "Asia/Bangkok";
+
+  try {
+    // With TZ=Asia/Bangkok (UTC+7, no DST) the local-time constructor
+    // interprets (2024, 0, 15, 12, 30, 45, 678) as
+    // 2024-01-15T12:30:45.678+07:00 = 2024-01-15T05:30:45.678Z.
+    const sent = new Date(2024, 0, 15, 12, 30, 45, 678);
+    expect(sent.toISOString()).toBe(EXPECTED_ISO);
+    expect(Intl.DateTimeFormat().resolvedOptions().timeZone).toBe("Asia/Bangkok");
+
+    await using sql = new SQL({ url, max: 1 });
+    const tableName = "ts_29208_" + randomUUIDv7("hex").replaceAll("-", "");
+
+    await sql`DROP TABLE IF EXISTS ${sql(tableName)}`;
+    await sql`CREATE TABLE ${sql(tableName)} (id INT PRIMARY KEY, ts DATETIME(3), tstz TIMESTAMP(3))`;
+
+    try {
+      await sql`INSERT INTO ${sql(tableName)} (id, ts, tstz) VALUES (${1}, ${sent}, ${sent})`;
+
+      // Binary (prepared statement) protocol.
+      const [bin] = (await sql`SELECT ts, tstz FROM ${sql(tableName)} WHERE id = 1`) as any[];
+      // Text (simple query) protocol.
+      const [txt] = (await sql`SELECT ts, tstz FROM ${sql(tableName)} WHERE id = 1`.simple()) as any[];
+
+      // Every column — binary and text, DATETIME and TIMESTAMP — must decode
+      // to the same UTC instant the client sent.
+      expect({
+        binaryDatetime: (bin.ts as Date).toISOString(),
+        binaryTimestamp: (bin.tstz as Date).toISOString(),
+        textDatetime: (txt.ts as Date).toISOString(),
+        textTimestamp: (txt.tstz as Date).toISOString(),
+      }).toEqual({
+        binaryDatetime: EXPECTED_ISO,
+        binaryTimestamp: EXPECTED_ISO,
+        textDatetime: EXPECTED_ISO,
+        textTimestamp: EXPECTED_ISO,
+      });
+    } finally {
+      await sql`DROP TABLE IF EXISTS ${sql(tableName)}`;
+    }
+  } finally {
+    if (savedTz === undefined) delete process.env.TZ;
+    else process.env.TZ = savedTz;
+  }
+}
+
+// ─── Docker path (used in CI) ───────────────────────────────────────────────
+// Not `concurrent: true` — this test mutates process.env.TZ, which is global.
+// Running in the default serial mode keeps the TZ flip isolated from any
+// other concurrent tests.
+if (isDockerEnabled()) {
+  describeWithContainer("issue #29208 (containerized MySQL)", { image: "mysql_plain" }, container => {
+    beforeAll(() => container.ready);
+    test("DATETIME/TIMESTAMP decode as UTC under non-UTC TZ", async () => {
+      await runRoundTrip(`mysql://root@${container.host}:${container.port}/bun_sql_test`);
+    });
+  });
+}
+
+// ─── Local-server path (used in dev/reproduction shells without Docker) ────
+//
+// Detection order:
+//   1. BUN_TEST_LOCAL_MYSQL_URL — explicit override.
+//   2. mysql://bun_test:bun_test_pw@127.0.0.1:3306/bun_sql_test — the farm
+//      convention; auto-provisioned via `mysql -u root` if reachable.
+//
+// Skipped cleanly if neither is available.
+describe("issue #29208 (local MySQL)", () => {
+  let resolvedUrl: string | undefined;
+
+  beforeAll(async () => {
+    const explicitUrl = process.env.BUN_TEST_LOCAL_MYSQL_URL;
+    if (explicitUrl) {
+      resolvedUrl = explicitUrl;
+      return;
+    }
+
+    // Idempotently auto-provision the farm-convention user. If the mysql
+    // CLI is missing or root isn't trusted, provisioning fails silently and
+    // the test becomes a no-op.
+    try {
+      await using proc = Bun.spawn({
+        cmd: ["mysql", "-u", "root"],
+        stdin: new TextEncoder().encode(
+          `CREATE DATABASE IF NOT EXISTS bun_sql_test;
+           CREATE USER IF NOT EXISTS 'bun_test'@'%' IDENTIFIED BY 'bun_test_pw';
+           GRANT ALL ON bun_sql_test.* TO 'bun_test'@'%';
+           FLUSH PRIVILEGES;`,
+        ),
+        stdout: "ignore",
+        stderr: "ignore",
+      });
+      if ((await proc.exited) === 0) {
+        resolvedUrl = "mysql://bun_test:bun_test_pw@127.0.0.1:3306/bun_sql_test";
+      }
+    } catch {
+      // mysql CLI unavailable — no local server path, rely on Docker above.
+    }
+  });
+
+  test("DATETIME/TIMESTAMP decode as UTC under non-UTC TZ", async () => {
+    if (!resolvedUrl) {
+      // No local MySQL — skip cleanly. CI relies on the Docker path above.
+      return;
+    }
+    await runRoundTrip(resolvedUrl);
+  });
+});