Show HN: I gave Claude a sundial and it built a calendar

31 lumbroso 7 7/16/2025, 2:55:31 PM github.com ↗

This is an open‑source Model Context Protocol (MCP) server that gives any LLM a sense of the passage of time.

Most MCP demos wire LLMs to external data stores. That’s useful, but MCP is also a chance to give models perception — extra senses beyond the prompt text.

Six functions (`current_datetime`, `time_difference`, `timestamp_context`, etc.) give Claude/GPT real temporal awareness: It can spot pauses, reason about rhythms, and even label a chat’s “three‑act structure”. Runs locally in <60 s (Python) or via a hosted demo.

If time works, what else could we surface? - Location / movement (GPS, speed, “I’m on a train”) - Weather (rainy evening vs clear morning) - Device state (battery low, poor bandwidth) - Ambient modality (user is dictating on mobile vs typing at desk) - Calendar context (meeting starts in 5 min) - Biometric cues (heart‑rate spikes while coding)

Curious what other signals people think would unlock better collaboration.

Full back story: https://medium.com/@jeremie.lumbroso/teaching-ai-the-signifi...

Happy to discuss MCP patterns, tool discovery, or future “senses”. Feedback and PRs welcome!

Comments (7)

cjlm · 13m ago

The sycophancy from Claude is incredibly jarring. I agree with Ethan Mollick that this could turn out to have more of a disastrous impact than AI hallucination.

https://www.linkedin.com/posts/emollick_i-am-starting-to-thi...

unshavedyak · 4m ago

It's even a blocker for some design patterns. Ie it's difficult to discuss options and choose the best one when the AI agrees with you no matter what. If you ask "But what about X" it is more likely to reverse course and agree with your new position entirely.

It's really frustrating. I've come to loathe the agreeable tone because every time i see it i remember the times where i've hit this pain point in design.

saberience · 6m ago

This title really doesn't fit what the submission did actually.

The submitter made a basic MCP function that returns the current time, so... Claude knows the current time. There is nothing about sundials and Claude didn't somehow build a calendar in any shape or form.

I thought this was something original or otherwise novel but it's not... it's not complex code or even moderately challenging code, nor is it novel, nor did it result in anything surprising... it's just a clickbaity title.

rlupi · 29m ago

Physical/mental health and personal journaling?

I just finished some changes to my own little project that provides MCP access to my journal stored in Obsidian, plus a few CLI tools for time tracking, and today I added recursive yearly/monthly/weekly/daily automatic retrospectives. It can be tweaked for other purposes (e.g. project tracking) tweaking the templates.

https://github.com/robertolupi/augmented-awareness

jayd16 · 14m ago

I was looking for the calendar app that was built but I guess it's metaphorical.

"We made an API for time so now the AI has the current time in it's context" is the bulk of it, yes?

morkalork · 5m ago

The current time (and location of the user, looking at you google gemini) is injected in most LLM chats now isn't it?

riedel · 14m ago

I am giving a lecture on context sensitive systems. One thing where all this context awareness failed was getting it into higher level reasoning and adapting program logic (think for example the android activity API). I was just telling the students that with MCPs as interface to all the context sources (like sensor based activity classifiers but definitely also time) we might overcome that challenge soon. Cool to see starting to implement that kind of stuff...