Brett Powell gives us a version of a time dimension in Power Query:
Like most dimensions in a data model, users will generally begin their analysis of time at a high level (e.g. hour) and then filter and drill their way into greater levels of detail, often leveraging hierarchies built into the model and/or drilling functionality in tools like Power BI. To support analysis by multiple grains and hierarchies, the query produces columns which group the seconds into hourly quartiles, hours, and minutes.
Gilbert Quevauvilliers has a script to generate a time dimension as well:
Below is the syntax to create a Time Dimension Table in Power Query
I had a requirement where I needed to create a Time Dimension for a customer. Most of the time I only need the date. Upon searching I could not find a resource where they had created the time dimension only using Power Query.
Gilbert’s gives you a key insight into the value of time dimensions: breaking everything out into periods. 5-minute intervals, 15-minute intervals, or however the company looks at data.