date of birth - as a JavaScript Date object (if missing or not a Date current date will be used; if before 1900-04-06 will be reset to 1900-04-06)
gender - enumerated string 'male or 'female' (if missing or illegal value supplied will be set to 'female')

and get back an object with properties:

date - Date object corresponding to the retirement date
age - Array containing age at retirement [y,m,d]

Example:

var sra = require('sra');

var dob = new Date('1959-02-20');
var gender = 'male';

var result = sra(dob, gender);

var d = result.date
// 2025-02-20

var a = result.age
var retirementAge = a[0]" years "+a[1]+" months "+a[2]+" days"
//  66 years 0 months 0 days

Specification

This module is based on HM Government State Pension Age timetable published by the Department for Work and Pensions update 15 May 2014 under the Open Government Licence v3.0.

The timetable is complicated because the government is both trying to unify retirement ages for men and women and also extend retirement age for both. The timetable is broken into specific tables applicable to different birth dates as follows:

Women

< 6/4/1950	60th birthday
6/4/1950 - 5/12/1953	specified in table 1 and 2

Men

< 6/12/1953

65th birthday

Men and Women

6/12/1953 - 5/10/1954	specified in table 3
6/10/1954 - 5/4/1960	66th birthday
6/4/1960 - 5/3/1961	specified in table 4
6/3/1961 - 5/4/1977	67th birthday
6/4/1977 - 5/4/1978	specified in table 5
> 5/4/1978	68th birthday