Depending on the livestock you keep (& you do mention you had issues with coral when doing this with your halides), an hour or so might work fine, but a huge shift is probably a bit much to expect your critters to get accustomed to. Eons of regular lighting periods in the tropics have no doubt conditioned the livestock we keep to do best with regular photo periods. I guess you could simply give it a try again with your current lighting & see how it goes.
The current photo period for my system is about 11-12 hours, from 07:30 to 19:00 (daylight savings) and I often wish I could enjoy the tank later into the evening as well. This has me thinking I might set up a nano in the living room & run that from noon to midnight.
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