We have two similar groups of words for today, 点VS小时，and 分VS分钟。 Here 点and 分are used to mean an exact point in time.
When used in a sentence, 点and 分are normally used as adverbial modifiers, so they are normally put before the verb.
However,小时and分钟are often used as predictive, which are normally put after the verb.
Additionally, we can use 半个小时 to mean 30 minutes. And, we can also use 半in the description of a point in time.