That's a cool idea but Google won't show me any commercial products like that, outside of commercial lighting intended for displays. Are you quite sure this actually exists? Make/model maybe? I'm wondering if it's actually the lamp doing that for some reason.
It would not help extend LED life but would make them more pleasant. Look at the documentation and see what it says about working with LEDs, that is to say, there are several methods of dimming, which one does it use? Get compatible "dimmable LEDs" and you should be fine. Even if they are not compatible, they'll come on when it ramps to full brightness.
Here's what you need to know about motion sensors.
- They already have a light sensor, and already won't turn on in daylight
- They need time to get acclamated. Interrupting power breaks that.
- When you connnect power to a motion sensor, it turns on for several seconds.
The motion sensor needs 24x7 power, not interrupted
A motion sensor needs power 24x7. A motion sensor needs to scan the environment repeatedly, get a sense for what "normal" looks like (and it may not be its first view), store that, and compare it to future scans.
Meanwhile the motion sensor's daylight sensor needs to calibrate itself to what day and night look like in the light location. It's not a matter of absolute lux - a light in a northern exposure in forest may see lower lux by daylight than one at night in an urban environment with street lights, traffic headlights and city glow. The sensor needs a day-night cycle or two to calibrate, and then it needs to store that data.
Your timer setup, designed to switch off plain lamps, is constantly cutting power to the motion sensor. Which does what, anyone? Anyone? Bueller?
Wipes out the motion sensor's memory. Now the motion sensor acts like a fresh install. First, it turns on regardless for a few seconds, to inform the installing electrician that the unit has good power. Then it falls back on factory settings for day/night lux until it learns (which it can't). It hasn't really had time to get clean scans of the area, it just sees this angry customer and has no idea if that guy is always there.
Sensor before switch?
The simple fix is to put the motion sensor ahead of the switch. The motion sensor has power 24x7, does its happy thing, and has no idea you have "cut the lamp connection" downstream. This only works on motion sensors with neutral wires. Oh wait. The timer needs power too.
This just doesn't work.
You have them wired in "And Logic", meaning light turns on if timer and sensor call for it. That can't work.
It is practical to wire "Or Logic", meaning the light turns on if either the motion sensor or timer calls for it. Motion sensors (with neutral) are happy being one of several things that turn a light ON. That's just not very useful.
Remembering that motion sensors already have light sensors and won't turn on in daylight.
Make up your mind
So really, this comes down to "junk the timer+switch" or "junk the motion sensor".
Honestly, motion sensors work fine if you give them an opportuntiy to settle in. Too many restless consumers don't, because they don't realize what's going on. Bypass (and eventually junk) the timer and switch.
Alternately, the timer would probably make a lot more sense if you had a plain light on it. Intermatic's steel chassis equipment is Good Stuff, if you junk it, disassemble it with respect and sell it on Craigslist.
Best Answer
Without looking for your particular model's instructions, many such lights have a manual override "built-in" by just flipping the power to them quickly - on-off-on within some time (that varies - might be as short as 5 seconds or as long as 30 seconds.)