Today marks Equal Pay Day, the day when women stop earning relative to men because of the gender pay gap. This year's Equal Pay Day falls on November 10, the same day as last year, according to the Fawcett Society, the UK's leading charity campaigning for gender equality and women's rights. This means women effectively work "for free" for 51 days a year. The gender pay gap is distinct from the issue of equal pay, because it reveals how roles of different seniority are being filled by either men or women. And the data published so far suggests men occupy a large majority of the best-paid positions.