Chrono

MCP server providing time, calendar, timezone, Chinese lunar calendar, almanac, and date utilities for AI agents.

Quick Start

Using npx (no installation needed)

npx mcp-chrono

Global install

npm install -g mcp-chrono
mcp-chrono

Usage with MCP Clients

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows):

{
  "mcpServers": {
    "chrono": {
      "command": "npx",
      "args": ["-y", "mcp-chrono"]
    }
  }
}

Claude Code

claude mcp add chrono -- npx -y mcp-chrono

Or with a custom data directory:

claude mcp add chrono -- npx -y mcp-chrono --data-dir /path/to/data

Cursor

Add to .cursor/mcp.json in your project root:

{
  "mcpServers": {
    "chrono": {
      "command": "npx",
      "args": ["-y", "mcp-chrono"]
    }
  }
}

Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "chrono": {
      "command": "npx",
      "args": ["-y", "mcp-chrono"]
    }
  }
}

Generic MCP client (mcp.json)

Any MCP-compatible client can use the standard mcp.json format:

{
  "mcpServers": {
    "chrono": {
      "command": "npx",
      "args": ["-y", "mcp-chrono"],
      "transportType": "stdio"
    }
  }
}

With custom data directory:

{
  "mcpServers": {
    "chrono": {
      "command": "npx",
      "args": ["-y", "mcp-chrono", "--data-dir", "/path/to/data"],
      "transportType": "stdio"
    }
  }
}

Data Directory

Holiday API responses are cached locally to avoid repeated network requests. Default location: ~/.mcp-chrono/

Override with --data-dir:

npx mcp-chrono --data-dir /tmp/mcp-chrono-data

Tools

Time & Timezone

get_current_time

Get current time in any IANA timezone with detailed components (timestamp, weekday, week of year, day of year, UTC offset, etc.)

Parameter	Type	Required	Default	Description
timezone	string	No	UTC	IANA timezone (e.g. Asia/Shanghai, America/New_York)
format	string	No	iso	Output format: iso, human, or relative

convert_timezone

Convert a datetime between two IANA timezones.

Parameter	Type	Required	Description
datetime	string	Yes	ISO 8601 datetime (e.g. 2024-01-15T10:30:00)
from_timezone	string	Yes	Source IANA timezone
to_timezone	string	Yes	Target IANA timezone

list_timezones

Search IANA timezones with current offsets and Chinese city names.

Parameter	Type	Required	Description
query	string	No	Search by timezone name, city, or Chinese name
continent	string	No	Filter by continent (e.g. Asia, Europe, America)

parse_timestamp

Parse Unix timestamps (seconds/milliseconds) or ISO 8601 strings into date components.

Parameter	Type	Required	Default	Description
input	string | number	Yes	-	Unix timestamp (seconds or milliseconds) or ISO 8601 string
timezone	string	No	UTC	IANA timezone for output

---

Date Calculation

calculate_time

Add/subtract time from a date. Returns a new date after applying the offset.

Three modes: gregorian (standard date arithmetic), lunar (Chinese calendar arithmetic), anchor (offset from a named festival like 春节 or Thanksgiving).

Parameter	Type	Required	Default	Description
mode	string	No	gregorian	Calculation mode: gregorian, lunar, or anchor
base_date	string	No	now	Base date in ISO format. Defaults to current time if omitted
timezone	string	No	UTC	IANA timezone for the base date
years	integer	No	-	Years to add (negative to subtract)
months	integer	No	-	Months to add (negative to subtract)
days	integer	No	-	Days to add (negative to subtract)
hours	integer	No	-	Hours to add (negative to subtract)
minutes	integer	No	-	Minutes to add (negative to subtract)
festival	string	No	-	Festival name for anchor mode (e.g. 春节, Christmas, Thanksgiving)
festival_year	integer	No	-	Year to resolve festival date for anchor mode

date_diff

Calculate the difference between two dates in years, months, days, hours, minutes, and total counts.

Parameter	Type	Required	Default	Description
start	string	Yes	-	Start date in ISO 8601 format
end	string	Yes	-	End date in ISO 8601 format
timezone	string	No	UTC	IANA timezone for parsing dates

countdown

Countdown from now to a target date with remaining days/hours/minutes/seconds.

Parameter	Type	Required	Default	Description
target	string	Yes	-	Target date/time in ISO 8601 format
timezone	string	No	UTC	IANA timezone for the target date

calculate_business_days

Count or add business days, skipping weekends and optionally public holidays (supports CN makeup workdays).

Parameter	Type	Required	Default	Description
action	string	Yes	-	count (count business days between two dates) or add (add business days to a date)
from	string	Yes	-	Start date in YYYY-MM-DD format
to	string	No	-	End date in YYYY-MM-DD format (required for count)
business_days	integer	No	-	Number of business days to add (required for add, negative to subtract)
country	string	No	-	Country code for public holidays (e.g. CN, US)
timezone	string	No	UTC	IANA timezone

---

Calendar & Festivals

convert_calendar

Convert between Gregorian and Chinese Lunar calendar. Returns Ganzhi (干支), zodiac, solar terms, festivals, constellation.

Parameter	Type	Required	Default	Description
direction	string	Yes	-	gregorian_to_lunar or lunar_to_gregorian
year	integer	Yes	-	Year
month	integer	Yes	-	Month (1–12)
day	integer	Yes	-	Day (1–31)
isLeapMonth	boolean	No	false	For lunar_to_gregorian: whether the month is a leap month (闰月)

get_festivals

List festivals, solar terms, and public holidays within a date range. Filterable by type.

Parameter	Type	Required	Default	Description
start_date	string	Yes	-	Start date in YYYY-MM-DD format
end_date	string	Yes	-	End date in YYYY-MM-DD format
country	string	No	CN	Country code for public holidays (e.g. CN, US, HK)
types	string[]	No	-	Filter by type: lunar_festival, solar_festival, solar_term, public_holiday

get_month_info

Month details: day count, first/last weekday, leap year, quarter, week count.

Parameter	Type	Required	Description
year	integer	Yes	Year (e.g. 2024)
month	integer	Yes	Month (1–12)

---

Chinese Almanac

get_almanac

Chinese almanac (黄历) for a date: 宜/忌 activities, lucky directions (喜神/财神/福神), conflict zodiac, 彭祖百忌, 吉神宜趋, 凶煞宜忌, 天神, 纳音, and more.

Parameter	Type	Required	Default	Description
date	string	No	today	Date in YYYY-MM-DD format

---

Persistent Countdowns

manage_countdown

CRUD for persistent countdown timers, stored as JSON on disk.

Parameter	Type	Required	Default	Description
action	string	Yes	-	set, get, list, or delete
id	string	No	-	Countdown ID (required for get / delete; auto-generated for set if omitted)
name	string	No	-	Name/description (required for set)
target_date	string	No	-	Target date in ISO 8601 format (required for set)
timezone	string	No	UTC	IANA timezone

Supported Regions

Region	Festivals	Public Holiday API
CN	27 festivals (lunar + solar)	timor.tech (includes makeup workdays)
US	10 federal holidays	date.nager.at
HK	17 public holidays (lunar, Easter, Ching Ming, fixed)	date.nager.at

License

MIT