Those old timers don't keep up with the changes in daylight and they are not reliable in areas with constant power outages. Here is a simple 5 to 15 dollar mod to keep them on when the should be and off when they need to be. This Instructables is focused on the plug in Malibu timers but can be used for a verity of plug in timers.
Step 1: Ditch the Timer!
Yep get rid of that old timer. The one in the box.
Step 2: Gather Your Weapons
You may have some specialty fasteners that will need a special torx tool or you can just file down the pin that is in some of the screw heads otherwise basic tools are all that is needed.
Step 3: Open Says Me
First unplug the power box if you haven't. Remove the covers and timer and mark the connections. I like to use color coded wire caps.
Step 4: Location Location Location
Pick a spot on the box exterior that will accommodate the mounting of the light sensor and not interfere with the internal components of the power box. I like to use painters tape to keep perspective of my measurements so I don't make too many mistakes.
Step 5: Drill and Fill
Drill the hole that will accommodate the sensor. I prefer the use of a hole saw but sheet metal snips can be used as well. Attach the sensor and connect using the instructions that came with the sensor.
Step 6: Assemble
Put things back the way you found them minus that pesky timer. If you have junior scientists/explorers living in your territory you should consider adding a screw to lock that lid down and prevent shocking life lessons from occurring.
Step 7: Fogeddabudit
Remount the power box and aim the sensor toward the source of natural light. That's it. Now it should go on in the dusk and off at dawn. Fin