Date & Time
Julian Day Converter
Convert dates to/from Julian Day Number and Julian calendar
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Quick start
Call this tool from your code in three languages.
cURL
curl -X POST 'https://api.elysiatools.com/en/api/tools/julian-calendar' \
-H 'Content-Type: application/json' \
-d '{"operation":"toJulianDay","gregorianDate":"2026-11-07","julianDay":"2460312.5","julianYear":"2024","julianMonth":"1","julianDayNum":"1"}'API reference
Send a POST request with your inputs as JSON. File parameters require a separate upload first.
Endpoint
HTTP
POST https://api.elysiatools.com/en/api/tools/julian-calendarParameters
| Name | Type | Required | Description |
|---|---|---|---|
| operation | select | Yes | — |
| gregorianDate | text | No | — |
| julianDay | text | No | — |
| julianYear | text | No | — |
| julianMonth | text | No | — |
| julianDayNum |
MCP integration
Add this tool to your Model Context Protocol server so AI agents can list and call it.
Server configuration
Add this block to your MCP client configuration:
mcp.json
{
"mcpServers": {
"elysiatools-julian-calendar": {
"name": "julian-calendar",
"description": "Convert dates to/from Julian Day Number and Julian calendar",
"baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=julian-calendar",
"command": "",
"args": [],
"env": {},
"isActive": true,
"type": "sse"
}
}
}List available tools
After connecting to the SSE endpoint, list the exposed tools:
tools/list
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
}Call this tool
Invoke the tool by its id, passing arguments built from its parameters:
tools/call
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "julian-calendar",
"arguments": {
"operation": "toJulianDay",
"gregorianDate": "2026-11-07",
"julianDay": "2460312.5",
"julianYear": "2024",
"julianMonth": "1",
"julianDayNum": "1"
}
}
}Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).
Questions or issues? Contact [email protected]