Yes that is correct -t he UK will recognise some marriages at the stroke of midnight, which will be two weeks before the first ceremonies will take place. So at at midnight, Celia Kitzinger and Sue Wilkinson will become one of the first same-sex couples to have their marriage recognised as legal under UK law.

Same-sex couples getting married in England and Wales will have to wait until Saturday 29th March to hold their ceremony but the change in law means couples who married overseas will have their unions automatically recognised from tomorrow onwards. This includes Celia Kitzinger and Sue Wilkinson, who married in Canada in 2003 and spent the last decade campaigning for their partnership to be recognised in Britain.
Tomorrow, due to the government’s decision to bring forward the Marriage (Same Sex Couples) Act, that day will finally come.

There’s no paperwork and no formal process. But when the day switches from Wednesday to Thursday all overseas same-sex marriages will at last be legally recognised; and for the first time there will be couples in Britain who are able to call themselves husband and husband, or wife and wife in the eyes of the law.