The halachic sources discuss if one missed counting one night, one can still count until night fall that day with the next day’s counting with a bracha. What is the extension of this? Could someone count like this for 2 or more days and then resume the next day’s count after night fall with a bracha?
The reason that one may count during the day if he missed the nighttime, is because it is still part of that day’s counting. Therefore although he missed counting the proper way, it would still be considered as if he counted b’dieved, and he may continue counting with a bracha from that night on. This will apply even if the next night he also forgot to count, and only remembered during the next day, since he didn’t miss the whole counting date. However if he missed a whole day, meaning the full 24 hour period, then he totally missed a counting date, and he should continue counting, but without a bracha. Therefore if someone missed two nights of counting (without counting during the daytime), he counts without a bracha from then on.
O:CH 489-7,8, M:B ibid 34