Time
Time is Anthropic's reference MCP server for clocks and timezones. It ships two tools: get_current_time, which returns the current time in an IANA timezone, and convert_time, which moves a wall-clock time from one zone to another. No account, no API key, no network calls at runtime. You run it locally with uvx as mcp-server-time.
How we started it
uvx mcp-server-timeUse it, and stop thinking about it. We started it and it answered initialize in 1,960 ms, reported itself as mcp-time 1.29.0, and published a tools/list of 1,199 bytes for 2 tools. The honest argument against is that this is a very small problem: a model that already knows the date only needs a clock when the answer must be correct, and you can hand it the timestamp yourself in a system prompt for zero tokens. If you are not doing that, this is the cheapest fix on the shelf.
Use it if
Skip it if
The bill for your context window
| Tool | Est. tokens | Described? | Required params |
|---|---|---|---|
| convert_time | ~190 | yes (30 chars) | 3 |
| get_current_time | ~109 | yes (39 chars) | 1 |
This is close to the floor of what an MCP server can cost you. The full tools/list is about 300 tokens (chars/4 estimate, measured 2026-08-19), split roughly 190 for convert_time and 109 for get_current_time, and the split makes sense: convert_time carries 3 required parameters and their schema, get_current_time carries 1. Against a median context tax across our batch that runs several times higher, and against the heaviest server we measured, this barely registers. Nothing here needs disabling.
Setup reality
There is nothing to configure. The harness scraped no env vars from it, because it wants none: no key, no token, no config file, no OAuth round trip. Transport is stdio, and the command is uvx mcp-server-time, which pulled 32 packages in 55ms on our box before the server came up. The only real prerequisite is uv on the machine running your client, which on a corporate laptop is sometimes the hard part. The README documents a local-timezone override flag if you do not want it guessing from the system clock.
Questions people ask
Does the time MCP server need an API key or internet access?
No. It reads the clock and the timezone database on the machine it runs on. Our probe ran it with a clean environment and no secrets, and it started normally with no env vars requested.
Why use an MCP clock when the model already knows the date?
It does not know it, it was told it, and only sometimes. The model has no clock, so anything time-sensitive is a guess unless something supplies the value. This server supplies it for roughly 300 tokens of tool schema.
What is the difference between get_current_time and convert_time?
get_current_time takes 1 required parameter, a timezone, and returns the time there now. convert_time takes 3, a source zone, a time, and a target zone, and returns the converted wall-clock time along with the offset.
How this page is made: the server is spawned as an unprivileged user with a clean environment and no credentials, then asked for its tools, resources and prompts over stdio. Token figures are estimates at four characters per token, not a tokenizer count. One run, one machine. Corrections: contact the desk.