There are a number of ways to set up control of your 12v lighting system.
 With a manual switch: When the electrician installs you outdoor power point have him add a switch beside the most convenient door which give access to the garden where the lighting system is installed so that you can switch it on and off easily as you require.
 With a daylight switch: A daylight switch turns the lighting system on when the outside light level drops to a preset level of darkness and turns the system off when the a preset level of light is attained again in the morning. With LED lightings system costing only cents per night to run there is no worry about large power bills. You can install the daylight switch either side of the transformer On/Off switchs
 With a timer unit: A timer unit can be either digital or analog and will turn the lighting system on and off depending on how the unit is programmed. The simplest way to install a timer is to buy a 240v timer and plug the transformer into the timer unit.
 With a remote control: Some people like to use remote controls. The easiest way to achive this control is with a 240v Remote Control Switch which plugs into the 24ov power point and then the transformer plugs into it.
 With a timer and a daylight switch: Some people do not want the lights to run all night or turn on when it is day time. A simple way to achieve this is to use a 240v timer switch and a daylight switch. The daylight switch (or transformer with the daylight switch installed) is plugged into the timer unit and a 6pm time is set to turn on. The daylight switch will not turn the lights on until the preset level of darkness is achieved, and then the timer will turn off the whole system at the time you want the lights to stop running eg 2am.