It has always been my understanding that LDN should be taken in conjunction with your sleep cycle...
When my son first started taking it, he would take it an hour or so before he went to bed for the evening. As he matured (he was only 13 when diagnosed) he started taking it at the same time every evening (10:30 p.m.) even though his actually bed time could be as late (or early) as 4 a.m.!
When he goes out for the evening and is in a situation where he believes he might forget, he will go ahead and take it mid to late afternoon.
I used to argue with him about this all the time, but after so long of it, we came to the conclusion that for him, it really didn't matter what time he took it, as long as he took it!
Since he grew up and escaped me constantly looking over his shoulder, he's not overly specific with his dosage time - but he never misses a dose within a 24 hour period.
I hope you do as well on LDN as he has for the past 6 years.