The problem with all of these anecdotal reports is there is too little information. The photo period is but one factor in using any light source.
For the photo period the be in any way useful we need at the least the following relevant information.
Height of the light from the water
Angle of light distribution -i.e. wide or spot
Settings for color and intensity of the light(s)
Depth of the coral in the tank
Water clarity - i.e. using carbon or not, frequency of water changes, skimmer
Type of coral
Frags or colonies
Alkalinity
Calcium
Magnesium
Are you feeding your corals
Circulation
Temp of tank and light's effect on temp

If people want to list all of thoes as well it would paint a better picture for sure but some are not really needed for me to get the answer I am looking for. Anyways I couldn't find any threads that discuss it in depth so maybe it would be a good thing to do.
Here is my list if anyone has suggestions shoot. The tank has been up for two months or so and acclimated to this 2040 at 100 percent for 3 weeks or so.
Height of the light from the water
-About 20" I think
Angle of light distribution -i.e. wide or spot
-No lenses just bare leds so I can get a good spread
Settings for color and intensity of the light(s)
-I need some more true white bulbs, there are none, its mainly blues and a few low k whites with reds and violets, way too blue for my liking!
Depth of the coral in the tank
-Bottom to 9 or 10" up in a 40 breeder
Water clarity - i.e. using carbon or not, frequency of water changes, skimmer
-carbon, Gfo (sometimes passive currently in a reactor with heavy feedings), big custom life reef skimz combo 5' high running recirculating, water changes weekly.
Type of coral
-Wild acros, mostly nubby thick branching acros
Frags or colonies
-Colonies and some average sized maricultures
Alkalinity
-8.5
Calcium
-380
Magnesium
-1375
Are you feeding your corals
-Coral snow and such when I get bored, I do heavy fish feedings and rely on them to feed the acros.
Circulation
-Mp40 ********* 90 percent, wp25 wave mode
Temp of tank and light's effect on temp
-75 to 77 or 78 degrees at peak light hours.
Basically I am wondering if a long photoperiod is needed or better with leds. I am used to running halides at 6 hours, which in my opinion was the same results as running them for 8 or 9.