DAX Function Guide

The HOUR function takes as argument the time that contains the hour you want to find. You can supply the time by using a date/time function, an expression that returns a datetime, or by typing the value directly in one of the accepted time formats. Times can also be entered as any accepted text representation of a time.

When the datetime argument is a text representation of the date and time, the function uses the locale and date/time settings of the client computer to understand the text value in order to perform the conversion. Most locales use the colon (:) as the time separator and any input text using colons as time separators will parse correctly. Review your locale settings to understand your results.