we use timers for most of ours, just plug the light into it, set 24 on and off periods, usually between 10 and 15 minute segments.. they are readilly availale b&q, asda woolworths etc about 3 to 4 quid each

this sort of thing...Buy 24 Hour Segment Timer. at Argos.co.uk - Your Online Shop for .

where we have lots, we plug a four plug extension into one of these, and four lights can be run from it, if only one then just plug in direct..