Continuous vs discrete dates in Tableau - Formula Comparison Trace

Sample Data

Daily sales data for five consecutive days in January 2024.

Cell	Value
A1	Date
B1	Sales
A2	2024-01-01
B2	100
A3	2024-01-02
B3	150
A4	2024-01-03
B4	120
A5	2024-01-04
B5	130
A6	2024-01-05
B6	170

Formula Trace

SUM([Sales]) by Continuous Date vs Discrete Date

Step 1: SUM([Sales]) for each date treating Date as continuous

Step 2: SUM([Sales]) for each date treating Date as discrete

Step 3: Visual difference: Continuous date axis vs Discrete date axis

Cell Reference Map

    A       B
1 | Date  | Sales |
2 | 1/1   | 100   |
3 | 1/2   | 150   |
4 | 1/3   | 120   |
5 | 1/4   | 130   |
6 | 1/5   | 170   |

Arrows: Date column feeds into the date axis (continuous or discrete), Sales column feeds into SUM aggregation.

Date and Sales columns are used. Date is the axis field, Sales is the measure summed.

Result

Continuous Date (Line Chart):
Date -> 1/1 --- 1/2 --- 1/3 --- 1/4 --- 1/5
Sales-> 100 --- 150 --- 120 --- 130 --- 170

Discrete Date (Bar Chart):
| 100 | 150 | 120 | 130 | 170 |
 1/1   1/2   1/3   1/4   1/5

Continuous dates show a smooth line connecting sales over time. Discrete dates show separate bars for each date.

Sheet Trace Quiz - 3 Questions

What does Tableau do when you use a continuous date on the axis?

A Shows dates as a smooth timeline with connected points

B Shows dates as separate categories with gaps

C Ignores the date and sums all sales

D Sorts dates alphabetically

Key Result

Continuous dates create a timeline axis; discrete dates create categorical groups.

Practice

1. In Tableau, what color pill represents a continuous date field on the Columns or Rows shelf?

easy

A. Green pill

B. Blue pill

C. Red pill

D. Yellow pill

Solution

1. Step 1: Understand Tableau date pill colors

   Tableau uses green pills for continuous fields and blue pills for discrete fields.

2. Step 2: Identify continuous date pill color

   Continuous dates appear as green pills to show smooth timelines.

3. Final Answer:

   Green pill -> Option A

4. Quick Check:

   Continuous date = Green pill [OK]

Hint: Continuous dates always show as green pills in Tableau [OK]

Common Mistakes:

• Confusing continuous with discrete pill colors
• Thinking blue pills represent continuous dates
• Assuming color depends on data type, not continuous/discrete

2. Which of the following is the correct way to convert a date field to discrete in Tableau?

easy

A. Right-click the date field and select 'Convert to Continuous'

B. Right-click the date field and select 'Convert to Discrete'

C. Drag the date field to Filters shelf

D. Double-click the date field to create a continuous axis

Solution

1. Step 1: Locate conversion options for date fields

   In Tableau, right-clicking a date field shows options to convert between continuous and discrete.

2. Step 2: Select the correct conversion for discrete

   Choosing 'Convert to Discrete' changes the pill color to blue and treats dates as categories.

3. Final Answer:

   Right-click the date field and select 'Convert to Discrete' -> Option B

4. Quick Check:

   Convert to Discrete = Right-click the date field and select 'Convert to Discrete' [OK]

Hint: Right-click date field to toggle continuous/discrete [OK]

Common Mistakes:

• Selecting 'Convert to Continuous' instead of discrete
• Dragging to Filters shelf does not change continuous/discrete
• Double-clicking creates continuous axis by default

3. Given a line chart with a continuous date on Columns and Sales on Rows, what happens if you change the date to discrete?

medium

A. The chart shows a smooth timeline with connected points.

B. The chart becomes empty because discrete dates are invalid.

C. The chart breaks into separate bars for each date value.

D. The chart shows a scatter plot with random points.

Solution

1. Step 1: Understand continuous date behavior in line charts

   Continuous dates create a smooth timeline with connected points forming a line.

2. Step 2: Understand discrete date behavior in line charts

   Discrete dates treat each date as a separate category, breaking the line into separate bars or marks.

3. Final Answer:

   The chart breaks into separate bars for each date value. -> Option C

4. Quick Check:

   Discrete date = separate categories [OK]

Hint: Discrete dates split timeline into separate categories [OK]

Common Mistakes:

• Expecting a smooth line with discrete dates
• Thinking discrete dates create scatter plots
• Assuming discrete dates cause errors or empty charts

4. You created a line chart with a continuous date but the axis shows unexpected gaps. What is the most likely cause?

medium

A. The date field is actually discrete, not continuous.

B. The date field is formatted as text.

C. The Sales measure is aggregated incorrectly.

D. There are missing dates in the data causing gaps.

Solution

1. Step 1: Check date field type

   Continuous dates create smooth axes; if gaps appear, the field is likely continuous, not discrete.

2. Step 2: Identify cause of gaps

   Missing dates in the data cause breaks in continuous timelines, showing gaps on the axis.

3. Final Answer:

   There are missing dates in the data causing gaps. -> Option D

4. Quick Check:

   Missing dates cause gaps in continuous axis [OK]

Hint: Gaps in continuous axis usually mean missing dates [OK]

Common Mistakes:

• Assuming date field is discrete when it's continuous
• Thinking text formatting causes axis gaps
• Blaming measure aggregation for axis gaps

5. You want to compare sales performance by month as distinct groups and also see the overall sales trend over time. How should you use continuous and discrete dates in your Tableau dashboard?

hard

A. Use discrete month for the bar chart and continuous month for the line chart.

B. Use continuous month for both charts to keep consistency.

C. Use discrete month for both charts to show clear categories.

D. Use continuous month for the bar chart and discrete month for the line chart.

Solution

1. Step 1: Understand visualization goals

   Comparing sales by month as distinct groups fits discrete dates (blue pills) for clear categories.

2. Step 2: Understand trend visualization

   Showing overall sales trend over time fits continuous dates (green pills) for smooth timelines.

3. Step 3: Apply correct date types per chart

   Use discrete month for bar chart to compare groups, continuous month for line chart to show trend.

4. Final Answer:

   Use discrete month for the bar chart and continuous month for the line chart. -> Option A

5. Quick Check:

   Discrete for groups, continuous for trends [OK]

Hint: Discrete = groups, Continuous = trends in Tableau dates [OK]

Common Mistakes:

• Using continuous dates for group comparisons
• Using discrete dates for trend lines
• Applying same date type to all charts regardless of purpose