So far as I can see, the next statutory accounts should cover the 12 months to 30/6/13 and should be submitted to Companies House within 9 months, that is, by 31/3/14. You can confirm this by looking at the Companies House website: http://wck2.companieshouse.gov.uk//wcframe?name=accessCompanyInfo
Also, you must pay Corporation Tax for y/e 30/6/13 by 1/4/14 (9 months and a day), and submit your tax return by 30/6/14 (one year).