# Retirement Countdown Calculator

> Computes the date on which a person reaches a chosen retirement age from their date of birth and counts the days, weeks, calendar months and Monday–Friday working days remaining from a reference date.

- Calculator id: `retirement-countdown` · Category: Time & Geography (`time`) · Tool name: `calculate_retirement_countdown`
- Canonical page: https://tttkmbb.com/time/retirement-countdown · This document: https://tttkmbb.com/time/retirement-countdown.md · JSON definition: https://tttkmbb.com/time/retirement-countdown.json

## Purpose

Computes the date on which a person reaches a chosen retirement age from their date of birth and counts the days, weeks, calendar months and Monday–Friday working days remaining from a reference date.

**Use when:** You want to know when someone reaches retirement age (default 67, the US full retirement age for people born in 1960 or later) and how long is left.

**Do not use when:** You need the savings required to retire (use retirement-savings or fire-number) or a pension-rule specific eligibility date; national retirement ages vary and must be entered explicitly.

## Input

| Parameter | Type | Unit | Required | Description |
| --- | --- | --- | --- | --- |
| `birth_date` | date |  | required | Date of birth (YYYY-MM-DD). |
| `retirement_age` | integer | years | optional, default 67 | Age at which retirement starts; 67 is the US Social Security full retirement age for people born in 1960 or later. (min 18, max 120) |
| `as_of_date` | date |  | optional, default "today" | Reference date for the countdown; defaults to the current UTC date. |

## Output

| Field | Type | Unit | Description |
| --- | --- | --- | --- |
| `retirement_date` | date |  | The birthday on which retirement_age is reached (29 February birthdays map to 1 March in common years). |
| `retirement_weekday` | string |  | Day of the week of the retirement date. |
| `current_age_years` | integer | years | Completed years of age on as_of_date. |
| `days_remaining` | integer | days | retirement_date − as_of_date; negative if the date has passed. |
| `weeks_remaining` | number | weeks | days_remaining / 7. |
| `months_remaining` | integer | months | Whole calendar months between the two dates (negative if passed). |
| `years_remaining` | number | years | days_remaining / 365.2425. |
| `remaining_text` | string |  | Years, months and days remaining ('ago' when the date has passed). |
| `working_days_remaining` | integer | days | Monday–Friday days after as_of_date up to and including retirement_date (public holidays not excluded); 0 if passed. |
| `status` | string |  | Countdown summary or notice that the retirement date has passed. |

## Formula

`retirement_date = birth_date + retirement_age years; days_remaining = retirement_date − as_of_date; weeks = days / 7; years = days / 365.2425; months = calendar months between the dates`

## Data Sources

- US Social Security Administration – Retirement age and benefit reduction — https://www.ssa.gov/benefits/retirement/planner/agereduction.html (government, retrieved 2026-09-24)
- Gregorian calendar – leap-year rule and month lengths (Wikipedia) — https://en.wikipedia.org/wiki/Gregorian_calendar (reference, retrieved 2026-09-24)

Data freshness: `daily` (max_age_seconds 86400). Depends on the current date unless the date is supplied.

## API

- `GET https://tttkmbb.com/api/v1/calculate/retirement-countdown?birth_date=…`
- `POST https://tttkmbb.com/api/v1/calculate/retirement-countdown` with JSON body `{"inputs": {…}}`
- Response: unified envelope (`success`, `request`, `result.values`, `result.units`, `sources`, `freshness`, `timestamp`, `next_actions`, `links`); see https://tttkmbb.com/docs/response-format.md
- Schema: https://tttkmbb.com/api/v1/calculators/retirement-countdown · OpenAPI operationId `calculate_retirement_countdown` in https://tttkmbb.com/openapi.json
- Authentication: none. Rate limit: fair use, see https://tttkmbb.com/docs/rate-limits.md.

## MCP

- Server: `https://tttkmbb.com/mcp` (Streamable HTTP, JSON-RPC 2.0, no auth)
- Tool:  `run_calculator` with `{"calculator_id": "retirement-countdown", "inputs": {…}}`

## Example

- Born 1970-06-15, retire at 67, as of 2026-09-23: inputs `{"birth_date":"1970-06-15","retirement_age":67,"as_of_date":"2026-09-23"}` → `{"retirement_date":"2037-06-15","retirement_weekday":"Monday","current_age_years":56,"days_remaining":3918,"weeks_remaining":559.7,"months_remaining":128,"years_remaining":10.73,"remaining_text":"10 years 8 months 23 days","working_days_remaining":2798}`
- Born 1960-03-01, retire at 65, as of 2026-09-23 (already passed): inputs `{"birth_date":"1960-03-01","retirement_age":65,"as_of_date":"2026-09-23"}` → `{"retirement_date":"2025-03-01","days_remaining":-571,"months_remaining":-18,"remaining_text":"1 year 6 months 22 days ago","working_days_remaining":0}`

```
GET https://tttkmbb.com/api/v1/calculate/retirement-countdown?birth_date=1970-06-15&retirement_age=67&as_of_date=2026-09-23
```

## Limitations

You need the savings required to retire (use retirement-savings or fire-number) or a pension-rule specific eligibility date; national retirement ages vary and must be entered explicitly. All values are computed from the formula above; no measurement or live data is involved.

## FAQ

**Which retirement age should I enter?**

The age that applies to your scheme: 67 for full US Social Security benefits (born 1960+), 66–67 for the UK State Pension, 65–67 in most EU countries, 60–65 for many occupational pensions. The calculator applies whatever you enter.

**How are working days counted?**

Every Monday to Friday between the day after as_of_date and the retirement date inclusive; public holidays and leave are not subtracted.

## Related

- [Age Calculator](https://tttkmbb.com/everyday/age.md) — Exact current age with next birthday.
- [Days Until Calculator](https://tttkmbb.com/everyday/days-until.md) — Countdown to any other date.
- [Compound Interest Calculator](https://tttkmbb.com/finance/compound-interest.md) — Grow retirement savings over the remaining years.