epochcalc

Epoch Calculator Time and date math that language models get wrong on their own: Unix timestamps, daylight-saving offsets, calendar arithmetic, and cron…

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What it can do

  • Time Now: The current time: Unix epoch in seconds and milliseconds, ISO 8601, and the local wall-clock time in a given IANA time zone with its current UTC offset and DST status. Use this before any re
  • Convert Timestamp: Convert a Unix timestamp (seconds or milliseconds; auto-detected unless unit is given) to a human-readable date in a time zone, with ISO 8601, RFC 2822, UTC offset, DST flag, weekda
  • Parse Datetime: Parse a date/time string (ISO 8601, RFC 2822, HTTP date, SQL "YYYY-MM-DD HH:mm:ss", or a Unix timestamp) into a Unix timestamp and a normalized description. Strings without an offset a

What data it sees

Do you need an account

No: the server works without sign-in

Epoch Calculator

Time and date math that language models get wrong on their own: Unix timestamps, daylight-saving offsets, calendar arithmetic, and cron schedules. Every calculation uses the IANA time zone database, the same engine behind epochcalc.com.

No API key, no signup, no state. Read-only.

Tools

Tool What it does
time_now Current time in any zone, with epoch seconds, ISO 8601, RFC 2822, and DST flag
convert_timestamp Unix timestamp (seconds or milliseconds, auto-detected) to a full date breakdown
parse_datetime Natural or ISO date string to timestamp and zone-aware fields
convert_timezone Same instant in two zones, with the hour difference and DST status of each
date_duration Days, weekdays, weeks, and calendar breakdown between two dates
epoch_math Add or subtract years, months, weeks, days, hours, minutes, or seconds
cron_next_runs Plain-English explanation of a cron expression plus its next N run times
days_until Countdown to a named holiday or event, or list the supported events

Notes

  • Time zones are IANA names such as America/New_York or Europe/Berlin. Abbreviations like EST are ambiguous and rejected.
  • Endpoint: https://epochcalc.com/mcp (Streamable HTTP, stateless). A plain JSON API for the same tools is at https://epochcalc.com/api/v1.
  • Documentation: epochcalc.com/api

How to connect

How to connect epochcalc to Claude

The server address to paste into Claude settings:

https://epochcalc--cmunkres.run.tools

  1. Open Claude (claude.ai or the desktop app).
  2. Go to Settings → Connectors.
  3. Click Add custom connector.
  4. Paste the server address copied below into Remote MCP server URL and click Add.
  5. In a chat, click + → Connectors and switch the new connector on.

Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

Authorization

After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

How to connect epochcalc to ChatGPT

The server address to paste into ChatGPT settings:

https://epochcalc--cmunkres.run.tools

  1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
  2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
  3. Open Settings → Connectors and click Create.
  4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
  5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
  6. In a new chat open + → Apps/Connectors and enable the connector.

OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

Authorization

On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

How to connect epochcalc to Cursor

The server address to paste into Cursor settings:

https://epochcalc--cmunkres.run.tools

Fastest: click Open in Cursor below and confirm the prompt.

Manually:

  1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
  2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
  3. Save the file. The server appears in the MCP list; authorize it there if asked.

Authorization

If the service needs sign-in, an authorize button appears next to the server in the MCP list.

Server tool list (8)

Raw names from tools/list. Only developers need these.

time_nowThe current time: Unix epoch in seconds and milliseconds, ISO 8601, and the local wall-clock time in a given IANA time zone with its current UTC offset and DST status. Use this before any relative date reasoning.
convert_timestampConvert a Unix timestamp (seconds or milliseconds; auto-detected unless unit is given) to a human-readable date in a time zone, with ISO 8601, RFC 2822, UTC offset, DST flag, weekday, and a relative phrase like "3 days ago".
parse_datetimeParse a date/time string (ISO 8601, RFC 2822, HTTP date, SQL "YYYY-MM-DD HH:mm:ss", or a Unix timestamp) into a Unix timestamp and a normalized description. Strings without an offset are interpreted in the given time zone.
convert_timezoneConvert a wall-clock date/time from one IANA time zone to another, correctly across daylight-saving transitions. Returns both sides with offsets, the hour difference at that instant, and whether either zone is on DST.
date_durationThe exact duration between two dates or date-times: calendar years/months/days, plus total days, hours, minutes and seconds, and the number of weekdays (Mon-Fri). Handles leap years and DST via the IANA database.
epoch_mathAdd to or subtract from a Unix timestamp in calendar-aware units (years, months, weeks, days, hours, minutes, seconds) in a time zone, e.g. "now + 30 days" or "1748736543 - 3 months". Returns the resulting timestamp in every format.
cron_next_runsExplain a 5- or 6-field cron expression in plain English and list its next run times in a time zone (as ISO 8601 and Unix timestamps). Use to answer "when does this cron job run next?" or to validate an expression.
days_untilCountdown to a holiday or to a date: days, hours and minutes remaining, and the next occurrence date. Pass an event slug (e.g. "christmas", "thanksgiving", "easter", "super-bowl") or a date (YYYY-MM-DD). Call with no arguments to list the known events.