Step 1: Adjust their light cycle appropriately.
Step 2: Harden them off
Step 3: Plant!
Step 1 is what seems to throw a lot of people off. When you move a plant from a 24 or even a 18 hour light cycle outside, then drop down to a lower cycle, they can start to flower on you, which is no good. For example, we are at 14 hours of light right now where I am at, so when you go from 24 or 18 down to 14 all of a sudden it can cause the plant to think it is fall and begin to flower.
However, this is strain dependent. Some can go from 24 or 18 outside with no adjustment and no issues. However in my experience, many cannot. Generally strains that finish earlier are more finicky and are easier to trigger - later finishing strains tend to handle the transition more easily.
It actually is not the length of light that causes flowering, but the length of darkness - that is what you need to look at. Hence it is not the 14 hours of light that makes the plant possibly trigger, it is the 10 hours of darkness.
IMO it is kinda late in the season since it usually takes time to adjust them. Since your clones are at 24 hours of light right now I think your best bet would be to try an "interrupted light cycle." Basically you set your main light cycle at what ever the length of the days are when you aim to plant, and then interrupt the night cycle with two hours of light right in the middle. So for example, if you were shooting to plant now, at 14 hours, you would set your cycle to do 14 hours on, 4 hours off, 2 hours on, 4 hours off, or 14/4/2/4. This way when the plants go outside in the natural light cycle, their light cycle is always getting longer so they do not trigger.
I can't be sure it will work this late in the year, but the interrupted light cycle worked well for me this year, however I started them on it 8 weeks before I planted. You could try moving them out form 24 hours with no adjustment and see what happens, but be prepared that some may start to flower on you.
For step 2 all you have to do is put them under shade cloth for a few days, then filtered sun for a few days and they will be good to go. The natural sunlight is much more powerful than any grow light so you have to transition them over a period of a week or so, or they will burn on you. You could do step 1 and step 2 at the same time if you have a cold frame and power at your garden.