Some shops are closed on Mondays and Sundays, or are open only in the afternoons of these days. On other days shops are usually open from 9am/9.30am until 5.30/6pm. Thursday evening or Friday evening is late opening, and most (if not all) shops are open until 9pm.
Most shops open on one or on all Sundays of the month.
Opening hours of most shops can be found here.
More on shopping is described in the See & Do section.