This post is a part of the PL-300: Microsoft Power BI Data Analyst Exam Prep Hub; and this topic falls under these sections:
Model the data (25–30%)
   --> Design and implement a data model
      --> Create a Common Date Table

Below are 10 practice questions (with answers and explanations) for this topic of the exam.
There are also 2 practice tests for the PL-300 exam with 60 questions each (with answers) available on the hub.

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Practice Questions

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Question 1

Why is creating a common date table recommended instead of using date columns directly from fact tables?

A. It reduces dataset size
B. It improves report rendering speed
C. It enables reliable time-intelligence calculations
D. It automatically creates relationships

✅ Correct Answer: C

Explanation:
DAX time-intelligence functions require a proper date table with contiguous dates. Using fact table date columns often leads to incorrect or blank results.

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Question 2

Which requirement must be met for a table to be marked as a Date table in Power BI?

A. It must contain a Year column
B. It must contain a unique, contiguous Date column
C. It must be created using DAX
D. It must be hidden from report view

✅ Correct Answer: B

Explanation:
A valid date table must contain a single column of unique dates with no gaps. This column is selected when marking the table as a Date table.

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Question 3

What happens if a date table is not marked as a Date table?

A. Relationships are disabled
B. Time-intelligence functions may not work correctly
C. Measures cannot be created
D. The model refresh fails

✅ Correct Answer: B

Explanation:
Marking a table as a Date table enables Power BI to correctly evaluate time-intelligence functions like TOTALYTD and SAMEPERIODLASTYEAR.

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Question 4

Which DAX function is commonly used to create a date table?

A. DATEADD
B. DATATABLE
C. CALENDAR
D. FORMAT

✅ Correct Answer: C

Explanation:
The CALENDAR() function generates a continuous date range, making it ideal for creating date tables in DAX.

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Question 5

A fact table contains Order Date and Ship Date columns. What is the recommended modeling approach?

A. Use one date table with two inactive relationships
B. Use auto date/time for both columns
C. Duplicate the date table for each role
D. Merge the two date columns

✅ Correct Answer: C

Explanation:
Duplicating the date table creates role-playing dimensions, allowing both relationships to remain active and slicers to work intuitively.

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Question 6

Which attribute is least likely to be included in a common date table?

A. Month Name
B. Quarter
C. Customer ID
D. Fiscal Year

✅ Correct Answer: C

Explanation:
A date table contains time-related attributes only. Customer ID belongs in a customer dimension.

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Question 7

Why is Auto Date/Time generally discouraged in enterprise Power BI models?

A. It increases refresh times
B. It limits customization and control
C. It disables relationships
D. It prevents DAX calculations

✅ Correct Answer: B

Explanation:
Auto Date/Time creates hidden tables that lack flexibility and are not ideal for advanced time-intelligence scenarios.

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Question 8

Which relationship configuration is most appropriate between a date table and a fact table?

A. One-to-one with bi-directional filtering
B. One-to-many with single-direction filtering
C. Many-to-many with bi-directional filtering
D. Many-to-one with bi-directional filtering

✅ Correct Answer: B

Explanation:
The date table should be on the one-side, filtering the fact table via single-direction filtering, consistent with star schema design.

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Question 9

What is a common mistake when creating a date table?

A. Including fiscal columns
B. Extending the date range beyond the fact data
C. Leaving gaps in the date sequence
D. Using Power Query

✅ Correct Answer: C

Explanation:
Date tables must contain continuous dates. Gaps can break time-intelligence calculations.

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Question 10

Which scenario most strongly indicates the need for a common date table?

A. Reports with only categorical data
B. Models without relationships
C. Reports using year-over-year comparisons
D. Importing a single Excel table

✅ Correct Answer: C

Explanation:
Year-over-year and other time-based comparisons depend on a properly configured date table.

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Final Exam Tips 🧠

• Always create and mark a date table
• Avoid relying on auto date/time
• Ensure dates are unique and contiguous
• Use role-playing dimensions for multiple date fields
• Think “time intelligence” whenever dates appear in a question

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