The first gay weddings in England and Wales can take place from March 29th, the UK Equalities Minister Maria Miller has announced.
Couples wishing to marry had thought they would have to wait until the summer after the Marriage (Same-Sex Couples) Act was passed in July.
However, now those wishing to be the first to be married there will be able to give notice of their intention on March 13th to marry on March 29th.
Announcing the date, Maria Miller said "Marriage is one of our most important institutions, and from March 29, 2014 it will be open to everyone, irrespective of whether they fall in love with someone of the same sex or opposite sex. This is just another step in the evolution of marriage and I know that many couples up and down the country will be hugely excited that they can now plan for their big day and demonstrate their love and commitment to each other by getting married".
Unlike civil partnerships, same-sex marriages would give the same legal recognition as marriage across a range of areas including pensions, inheritance, child maintenance and immigration rights.
While the change will not be enforced upon religious organisations, they will be able to opt in. However, there is a provision in the law which bans the Church of England and the Church of Wales from holding gay marriages.
Ms. Miller said she was "working hard" to ensure that couples wishing to convert civil partnerships into marriages would be able to do so before the end of next year.
Those wishing to take part in same-sex weddings in some British consulates and Armed Forces bases overseas or in military chapels will have to wait until June.
Ben Summerskill, chief executive of UK gay rights campaign group Stonewall, said he was "delighted" at the announcement, which he said was "particularly resonant" as it came on United Nations Human Rights Day.
He said "This historic step will mean that, for the first time, every gay person in England and Wales will finally enjoy exactly the same rights as their heterosexual friends and family."
The British Deputy Prime Minister tweeted under #savethedate saying "Great news that same sex weddings will happen from 29th March 2014".
The Irish government previously announced a referendum on same-sex marriage rights would take place here in the first half of 2015.
Latest opinion polls show that 76% of Irish voters would vote in favour of gay marriage in any such referendum.
