Shabnam Watson runs an experiment:
As you may have already heard, one of the easiest ways to reduce a Power BI model (dataset) size is by splitting DateTime columns into separate Date and Time columns but the question is how much space reduction can you achieve by doing so. As I show in this blog post, the reduction can be significant and up to % 80 or % 90 depending on the number and cardinality of the datetime columns.
That’s a lot of savings.