to parse date information into datetime from user message before sending to tools for API search

[TMCHAN75]

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Example Code

@tool
def get_opening_hours(DD):
    """Use this to get the opening hours of a day of the company."""
 
    #if DD == 'today':
    #    DD = date.today().strftime('%Y-%m-%d')

# DD should be in YYYY-MM-DD format
    url = f"https://xxxxxx/json/opening_hours_{DD}.json"

Description

I run a simple langgraph application based on ChainLit Langgraph integration example: https://docs.chainlit.io/integrations/langchain

I created "get_opening_hours" tool , and it is workable ;
The "get_opening_hours" tool take the "param" from tool_call passing. and it will use the "param" to do an API call.

If I ask a question "What is the opening hours of today? " langgraph will trigger "get_opening_hours" tool with param= "today".
however, "today", is not in YYYY-MM-DD format, and the API call fails.

I used to build a chatbot with the below prompt to parse the date information:

                                "description": "The date in 'YYYY-MM-DD' format. Today is " + today_date +". Get The date of the opening hours in yyyy-mm-dd format. e.g. If today is 2024-09-17, Tomorrow means 2024-09-18, Next wednesday means 2024-09-23, no pecific date means Today's date 2024-09-17.",

QUESTION:
I am new in LangGraph , and I would like to get your advice how to parse date information from user message?
Thanks in advance

System Info

System Information

OS: Windows
OS Version: 10.0.26100
Python Version: 3.12.9 (tags/v3.12.9:fdb8142, Feb 4 2025, 15:27:58) [MSC v.1942 64 bit (AMD64)]

Package Information

langchain_core: 0.3.35
langchain: 0.3.19
langchain_community: 0.3.17
langsmith: 0.3.8
langchain_ollama: 0.2.3
langchain_openai: 0.3.6
langchain_text_splitters: 0.3.6
langgraph_sdk: 0.1.51

Optional packages not installed

langserve

Other Dependencies

aiohttp<4.0.0,>=3.8.3: Installed. No version info available.
async-timeout<5.0.0,>=4.0.0;: Installed. No version info available.
dataclasses-json<0.7,>=0.5.7: Installed. No version info available.
httpx: 0.28.1
httpx-sse<1.0.0,>=0.4.0: Installed. No version info available.
jsonpatch<2.0,>=1.33: Installed. No version info available.
langchain-anthropic;: Installed. No version info available.
langchain-aws;: Installed. No version info available.
langchain-cohere;: Installed. No version info available.
langchain-community;: Installed. No version info available.
langchain-core<1.0.0,>=0.3.34: Installed. No version info available.
langchain-core<1.0.0,>=0.3.35: Installed. No version info available.
langchain-deepseek;: Installed. No version info available.
langchain-fireworks;: Installed. No version info available.
langchain-google-genai;: Installed. No version info available.
langchain-google-vertexai;: Installed. No version info available.
langchain-groq;: Installed. No version info available.
langchain-huggingface;: Installed. No version info available.
langchain-mistralai;: Installed. No version info available.
langchain-ollama;: Installed. No version info available.
langchain-openai;: Installed. No version info available.
langchain-text-splitters<1.0.0,>=0.3.6: Installed. No version info available.
langchain-together;: Installed. No version info available.
langchain-xai;: Installed. No version info available.
langchain<1.0.0,>=0.3.18: Installed. No version info available.
langsmith-pyo3: Installed. No version info available.
langsmith<0.4,>=0.1.125: Installed. No version info available.
langsmith<0.4,>=0.1.17: Installed. No version info available.
numpy<2,>=1.26.4;: Installed. No version info available.
numpy<3,>=1.26.2;: Installed. No version info available.
ollama: 0.4.7
openai<2.0.0,>=1.58.1: Installed. No version info available.
orjson: 3.10.15
packaging<25,>=23.2: Installed. No version info available.
pydantic: 2.10.6
pydantic-settings<3.0.0,>=2.4.0: Installed. No version info available.
pydantic<3.0.0,>=2.5.2;: Installed. No version info available.
pydantic<3.0.0,>=2.7.4: Installed. No version info available.
pydantic<3.0.0,>=2.7.4;: Installed. No version info available.
pytest: Installed. No version info available.
PyYAML>=5.3: Installed. No version info available.
requests: 2.32.3
requests-toolbelt: 1.0.0
requests<3,>=2: Installed. No version info available.
rich: Installed. No version info available.
SQLAlchemy<3,>=1.4: Installed. No version info available.
tenacity!=8.4.0,<10,>=8.1.0: Installed. No version info available.
tenacity!=8.4.0,<10.0.0,>=8.1.0: Installed. No version info available.
tiktoken<1,>=0.7: Installed. No version info available.
typing-extensions>=4.7: Installed. No version info available.
zstandard: 0.23.0