Objectives in this domain

Write date, string, logical and Boolean, number, type-conversion, aggregate, and basic spatial calculations.
Section 2.1medium
Build and customise table calculations - moving and window averages, percent of total, running total, difference and percent difference, percentile, index, and ranking.
Section 2.3hard
Apply dimension and measure filters, configure Top/Bottom N, wildcard, include, exclude, and conditional filters, add filters to context, and apply filters across multiple sheets and data sources.
Section 2.4medium
Create parameters to drive interactivity in calculations, filters, and reference lines, and set parameters to refresh dynamically.
Section 2.5medium
Structure data using sets, bins, hierarchies, and groups.
Section 2.6medium
Create symbol maps, density maps, and choropleth (filled) maps, and add mark layers.
Section 2.7medium
Summarise, model, and customise data using totals and subtotals, reference lines and bands, average and trend lines, distribution bands, and forecasting.
Section 2.8medium
Write FIXED, INCLUDE, EXCLUDE, and nested level of detail (LOD) calculations.
Section 2.9hard

Sample question from this domain

Free sampleExplore and Analyze Datamedium

A subscriptions dataset has a [Signup Date] and a [Cancel Date] field, both stored as dates. An analyst needs a calculated field that returns the whole number of complete months each customer stayed subscribed, so that a customer who signed up on 15 January and cancelled on 14 March counts as one month rather than two. Which calculation returns the correct result?

// Sample row:
// [Signup Date] = 2024-01-15
// [Cancel Date] = 2024-03-14
// Expected result = 1

ADATEDIFF('month', [Cancel Date], [Signup Date]) - IIF(DAY([Cancel Date]) < DAY([Signup Date]), 1, 0)
BDATEPART('month', [Cancel Date]) - DATEPART('month', [Signup Date]) - IIF(DAY([Cancel Date]) < DAY([Signup Date]), 1, 0)
CDATEDIFF('month', [Signup Date], [Cancel Date]) + IIF(DAY([Cancel Date]) < DAY([Signup Date]), 1, 0)
DDATEDIFF('month', [Signup Date], [Cancel Date]) - IIF(DAY([Cancel Date]) < DAY([Signup Date]), 1, 0) Correct

Understand that DATEDIFF with the 'month' part counts calendar boundaries crossed, not complete elapsed months. DATEDIFF('month', start, end) counts how many times the month boundary is crossed between the two dates, regardless of the day component, so it reports two for 15 January to 14 March. To get complete elapsed months you subtract one whenever the end day has not yet reached the start day.

Why A is wrong: The day-adjustment is correct but the two date arguments are reversed, so DATEDIFF returns a negative value for any customer who cancels after signing up. The dates must run start then end.

Why B is wrong: Subtracting month numbers ignores the year, so it miscounts across year boundaries and returns a negative figure when the cancel month is numerically lower than the signup month.

Why C is wrong: Adding rather than subtracting one inflates the count further; DATEDIFF already over-counts when the end day is earlier, so the correction must reduce the total, not increase it.

Why D is correct: DATEDIFF with 'month' counts calendar-month boundaries crossed, so it over-counts by one when the end day has not yet reached the start day; subtracting one in that case yields complete elapsed months.

Other domains in this exam

Connect to and Transform Data24% of the exam
Create Content26% of the exam
Publish and Manage Content on Tableau Server and Tableau Cloud9% of the exam

See also the Analytics-DA-201 cert hub, the study guide, and the cheat sheet.