time server not working

[robotdad]

The MCP time server is not working on Windows. Logs below.

Installed 22 packages in 3.65s
Traceback (most recent call last):
File "C:\Users\mgoodner\AppData\Local\Programs\Python\Python311\Lib\zoneinfo_common.py", line 12, in load_tzdata
return resources.files(package_name).joinpath(resource_name).open("rb")
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\mgoodner\AppData\Local\Programs\Python\Python311\Lib\pathlib.py", line 1044, in open
return io.open(self, mode, buffering, encoding, errors, newline)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory: 'C:\Users\mgoodner\AppData\Local\uv\cache\archive-v0\ffmqKEu2d_J95JnRz3Y0o\Lib\site-packages\tzdata\zoneinfo\Pacific Standard Time'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "", line 198, in run_module_as_main
File "", line 88, in run_code
File "C:\Users\mgoodner\AppData\Local\uv\cache\archive-v0\ffmqKEu2d_J95JnRz3Y0o\Scripts\mcp-server-time.exe_main.py", line 8, in
File "C:\Users\mgoodner\AppData\Local\uv\cache\archive-v0\ffmqKEu2d_J95JnRz3Y0o\Lib\site-packages\mcp_server_time_init.py", line 15, in main
asyncio.run(serve(args.local_timezone))
File "C:\Users\mgoodner\AppData\Local\Programs\Python\Python311\Lib\asyncio\runners.py", line 190, in run
return runner.run(main)
^^^^^^^^^^^^^^^^
File "C:\Users\mgoodner\AppData\Local\Programs\Python\Python311\Lib\asyncio\runners.py", line 118, in run
return self._loop.run_until_complete(task)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\mgoodner\AppData\Local\Programs\Python\Python311\Lib\asyncio\base_events.py", line 654, in run_until_complete
return future.result()
^^^^^^^^^^^^^^^
File "C:\Users\mgoodner\AppData\Local\uv\cache\archive-v0\ffmqKEu2d_J95JnRz3Y0o\Lib\site-packages\mcp_server_time\server.py", line 119, in serve
local_tz = str(get_local_tz(local_timezone))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\mgoodner\AppData\Local\uv\cache\archive-v0\ffmqKEu2d_J95JnRz3Y0o\Lib\site-packages\mcp_server_time\server.py", line 45, in get_local_tz
return ZoneInfo(str(tzinfo))
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\mgoodner\AppData\Local\Programs\Python\Python311\Lib\zoneinfo_common.py", line 24, in load_tzdata
raise ZoneInfoNotFoundError(f"No time zone found with key {key}")
zoneinfo._common.ZoneInfoNotFoundError: 'No time zone found with key Pacific Standard Time'

[g-votte]

The same error happens with macOS.

Repro

Run the following commands:

pip install mcp-server-time
python -m mcp_server_time

We can also reproduce with uvx:

uvx mcp-server-time

I saw the problem with mcp-server-time==0.6.2:

pip freeze | grep mcp-server-time
mcp-server-time==0.6.2

Analysis

This error occurs during server launch, specifically when --local-timezone is not specified.

The issue is in these lines:

servers/src/time/src/mcp_server_time/server.py

Lines 43 to 45 in c5968be

	tzinfo = datetime.now().astimezone(tz=None).tzinfo
	if tzinfo is not None:
	return ZoneInfo(str(tzinfo))

datetime.now().astimezone().tzinfo returns a non-IANA format on macOS and Windows, which causes an error when passed to ZoneInfo(str(tzinfo)).

Workaround

We can avoid this issue by using Docker:

"mcpServers": {
  "time": {
    "command": "docker",
    "args": ["run", "-i", "--rm", "mcp/time"]
  }
}

Possible Solutions

While this issue isn't critical thanks to the official Docker image, we should either implement a platform-independent solution or explicitly document the supported platforms.

Possible approaches:

• Document that running via uvx/python on macOS/Windows is not supported
• Introduce a package to reliably get IANA timezone format (e.g., tzlocal)
• Fall back to UTC as the default timezone