How to Group Dates in Tableau

Working with dates in Tableau is fundamental to building useful dashboards, but getting them to look and behave exactly how you want can be tricky. You often need to group dates into bigger buckets - like weeks, months, or quarters - to see meaningful trends instead of daily noise. This guide breaks down the different ways to group dates in Tableau, from the simple click-of-a-button method to more advanced custom calculations.

We'll walk through three practical approaches for grouping your date fields. Whether you need a quick overview or a highly customized financial report, you’ll find a method here that fits your needs.

Why Group Dates in Tableau?

Before jumping into the "how," it's helpful to understand the "why." Raw date data, especially at a daily or hourly level, is often too granular. Showing sales for every single day of the year on a line chart usually results in a chaotic, spiky mess that's hard to interpret. Grouping dates helps you:

Identify Trends: Aggregating daily data into weeks, months, or quarters smooths out random fluctuations, making it easier to spot underlying patterns like seasonality or long-term growth.
Simplify Visualizations: Grouped dates lead to cleaner, more readable charts. A bar chart with 12 bars for monthly sales is much easier to understand than one with 365 bars for daily sales.
Compare Time Periods: Grouping is essential for creating common business comparisons like Month-over-Month (MoM), Quarter-over-Quarter (QoQ), or Year-over-Year (YoY) performance reports.
Align with Business Cycles: Your business might operate on fiscal quarters, bi-weekly sprints, or seasonal campaigns. Custom date grouping allows you to analyze data within these specific business contexts.

Method 1: Using Tableau's Built-in Date Hierarchy (The Easy Way)

Tableau knows that looking at data by various time periods is incredibly common, so it provides a built-in hierarchy for every date field you use. This is the quickest and most straightforward way to group dates.

When you drag a date field onto the Rows or Columns shelf, Tableau automatically defaults to grouping it by year. You'll see a blue pill that says something like YEAR(Order Date). This pill has a small "+" symbol on its left side, which is your key to the date hierarchy.

Here’s how to use it, step-by-step:

Connect to your data source and drag your date dimension (e.g., "Order Date") onto the Columns shelf.
Tableau will create a blue YEAR(Order Date) pill, and your view will show columns for each year in your data.
Click the "+" sign on the YEAR(Order Date) pill. Tableau will add a QUARTER(Order Date) pill next to it, breaking down each year by quarter.
Click the "+" on the quarter pill, and you’ll get MONTH(Order Date). You can continue drilling down all the way to the day or even hour and minute, depending on your data's granularity.

This hierarchy lets you quickly explore your data at different levels. If you want to remove a level, simply click the "-" sign on the pill or drag the pill you no longer want off the shelf.

Understanding Blue vs. Green Date Pills (Discrete vs. Continuous)

You've likely noticed that pills in Tableau are either blue or green. This is a very important concept for working with dates.

Blue Pills (Discrete): These represent individual, distinct categories. When you use a discrete date part like MONTH(Order Date), Tableau treats each month (January, February, March) as a separate label or header. It will show you data for all Januaries combined, regardless of the year, unless you also have YEAR(Order Date) in the view to break it down.
Green Pills (Continuous): These represent values on a continuous axis. When you change a date to continuous, Tableau sees it as a point on a timeline. A continuous Month pill will show January 2022, followed by February 2022, then March 2022, and so on, creating a proper time-series axis.

To switch between discrete and continuous, right-click the date pill on a shelf and select the type you want from the bottom half of the menu. Choosing a "Date Part" (e.g., Month or Year in the first section of the menu) will make it discrete (blue). Choosing a "Date Value" (e.g., Month or Year in the second section with the line chart icon) will make it continuous (green).

Method 2: Creating Custom Dates

The default hierarchy is great for quick exploration, but sometimes you need more specific or permanent groupings. What if you only want to group by "Month and Year" without having to drill down every time? That’s where Custom Dates come in.

Creating a Custom Date generates a new dimension in your Data Pane, which you can then use like any other field.

Here’s how to create one:

In the Data pane on the left, right-click on your original date field (e.g., Order Date).
Select Create → Custom Date....
A dialog box will appear. Give your custom date a name, like "Order Month/Year".
Under the Detail dropdown, select the level you want. You have options like "Year," "Month," "Week Numbers," and "Month / Year." Let’s choose "Month / Year" for this example.
Below that, you’ll see radio buttons for "Date Part" and "Date Value."
- Date Part: Creates a discrete (blue) measure. If you select "Weeks," it will only give you the week number (1-52), which can be good for comparing performance across all "Week 1s" of the year.
- Date Value: Creates a continuous (green) date dimension. Choosing "Month / Year" as a date value will create a new field where every date is truncated to the first day of its month (e.g., 'January 1, 2023,' 'February 1, 2023'). This is ideal for line charts showing trends over time.
Click OK.

Your new custom date field (e.g., "Order Month/Year") will appear in the Data Pane. Now you can drag this single pill into your view to get the exact grouping you need without any further clicks.

Method 3: Grouping with Calculated Fields (For Maximum Flexibility)

When the standard options aren't enough, Calculated Fields give you complete control to define custom date groups based on your specific business logic. This is the most powerful method and can solve almost any date grouping problem you encounter.

To create one, right-click anywhere in the whitespace of the Data pane and select Create Calculated Field. Then, use Tableau's functions to write your logic.

Example 1: Grouping by Weekday vs. Weekend

Let's say you want to compare how sales perform on weekdays versus weekends. This isn’t a standard date aggregation, so a calculated field is perfect.

Create a calculated field named "Weekday/Weekend" with the following formula:

How it works: The DATEPART('weekday', [Order Date]) function returns a number from 1 (Sunday) to 7 (Saturday). This formula checks if the day is a Sunday (1) or a Saturday (7) and labels it as "Weekend", otherwise, it's a "Weekday." Now you have a new dimension you can use to slice and dice your data.

Example 2: Grouping into Custom Periods (e.g., Campaign Launch)

Imagine your company launched a major marketing campaign on March 15, 2023, and you want to analyze performance "Before" vs. "After" that date.

Create a calculated field named "Campaign Period" with this logic:

How it works: This formula checks if the Order Date is before March 15, 2023. Tableau recognizes dates wrapped in hash symbols (#YYYY-MM-DD#). This creates a simple two-category dimension that you can use to compare metrics instantly.

Example 3: Creating Custom Fiscal Quarters

Many companies' financial years don't start on January 1st. If your fiscal year starts on April 1st, Tableau's default quarters won't align with your financial reports. You can create a calculated field to fix this.

Create a Calculated Field named "Fiscal Quarter" with this formula:

Let’s go a simpler route and just calculate the right quarter number. What if your fiscal year starts in July (Month 7)?

How it works: The DATEADD('month', -6, [Order Date]) function shifts every date back by 6 months. For a date in July, this function treats it as if it were January. The DATEPART('quarter', ...) function then calculates the quarter for that shifted date. So, July becomes Q1, October becomes Q2, and so on. This gives you proper fiscal quarters that you can then use in all your financial reporting.

Final Thoughts

Mastering how to handle and group dates is a huge step toward becoming proficient in Tableau. We covered the three main methods you'll use: the built-in hierarchy for quick drill-downs, creating custom dates for clean, reusable groupings, and calculated fields for ultimate control over your business logic. Start with the simplest method that solves your problem and work your way up to calculations as your questions become more complex.

Wrangling dates, creating calculations, and joining different data sources is often where data analysis gets time-consuming. At Graphed , we aim to eliminate this friction. We allow you to connect all your marketing and sales data sources - like Google Analytics, Shopify, and Salesforce - into one place and then build entire dashboards just by describing what you want to see in plain English. Instead of learning functions like DATEADD, you can simply ask, “Show me sales by fiscal quarter, starting in April,” and instantly get the correct visualization, all in a live dashboard.