Looker Studio Function : FORMAT_DATETIME

Category: DATE function

The FORMAT_DATETIME function in Looker Studio is used to convert a DATETIME value into a formatted string based on a specified pattern. It helps customize how date and time values appear in dashboards, making them easier to read, compare, and present professionally.

This function is extremely useful when displaying formatted dates such as
01 Jan 2025 instead of 2025-01-01 00:00:00.

Purpose of the FORMAT_DATETIME Function 

1. Improve readability

Display datetime values in a more meaningful and presentable format

2.Support localization 

Change display format based on region (e.g., DD-MM-YYYY)

3. Convert datetime to text 

Useful when merging with text fields.

Why Use FORMAT_DATETIME in Looker Studio?

Key Benefits & Use Cases

✔ Convert system-formatted datetime values to custom display formats
✔ Improve reporting clarity for end-users and stakeholders
✔ Display readable timestamps in tables and scorecards
✔ Combine formatted datetime with labels using CONCAT
✔ Convert datetime before exporting or sharing reports


FORMAT_DATETIME(format_string, datetime_expression)

ParameterTypeDescription
format_string String Date-time pattern of the original string
datetime_expression DateTime 

How the FORMAT_DATETIME Function Works?

It transforms a DATETIME field into a text string based on the specified format.
Formatting symbols (like %d, %Y, %b, %H) determine the output style.

When should use the FORMAT_DATETIME Work?

Use it when:

  • You need readable date & time in dashboards

  • You must convert datetime to a formatted string before concatenation

  • You want to format timestamps before export

  • You are building executive dashboards, print layouts, or client presentations

Examples of FORMAT_DATETIME?

Example 1: Display Date Like 15 June 2025

FORMAT_DATETIME("%d %B %Y", Order_Time)

Output:
15 June 2025

Example 2: Convert Datetime to DD-MM-YYYY Format

FORMAT_DATETIME("%d-%m-%Y", Created_At)

Output:
05-01-2025


Example 3: Including Time (24-hour format)

FORMAT_DATETIME("%d-%m-%Y %H:%M:%S", Timestamp)

Output:
05-01-2025 14:20:30

Tips & Best Practices

💡 Use FORMAT_DATETIME for readability—not calculations (it returns text)
💡 For calculations, keep the original datetime field
💡 Combine with CONCAT to create formatted labels
💡 Localize formats depending on audience (India vs US formats)
💡 Use PARSE_DATETIME before formatting if data is text

1. What does FORMAT_DATETIME do?

It converts a datetime value into a formatted text string for better readability.

2. Can I use FORMAT_DATETIME for date-only fields?

Yes, but FORMAT_DATE may be more appropriate if time is not needed.

3. Does FORMAT_DATETIME change the actual date value?

No—it only changes how it’s displayed.

4. Can I use FORMAT_DATETIME in time-series charts?

No—since it returns a string, use the original datetime for chart metrics.

5. What if my data is text, not datetime?

Use PARSE_DATETIME() first to convert text to datetime.