In England and Wales, stores that are over 280 square metres are allowed to open for six continuous hours, between the hours of 10am and 6pm (for example 10am – 4pm).  Small stores (those under 280 square metres, which is roughly the size of a doubles tennis court) do not have any restrictions on Sunday opening hours. 

Large stores (over 280 square metres) are not permitted to open at all on Easter Sunday and Christmas Day. 

Full details of the legislation are available on the Gov.uk website here: https://www.gov.uk/trading-hours-for-retailers-the-law