A determiner is a word, such as a number, article, personal pronoun, that determines (limits) the meaning of a noun. Most of your time would imply more than half, the most time implies more than the. During most of history, humans were too busy to think about thought.
'This Is When the Team Needs Me the Most' Al Horford Drops Meaningful
Why is most of history correct in the above sentence? I've recently come across a novel called a most wanted man, after which being curious i found a tv episode called a most unusual camera. Most is what is called a determiner.
Most is defined by the attributes you apply to it.