Simplifying Data Interpretation: A Comprehensive Guide to Understanding and Using the DATETIME_TRUNC Function in Looker Studio

 Simplifying Data Interpretation: A Comprehensive Guide to Understanding and Using the DATETIME_TRUNC Function in Looker Studio

In the world of Google Data Studio, the DATETIME_TRUNC function serves to simplify your data interpretation. This function allows you to truncate a date down to a specific granularity or 'part' that you select.

The aim of this is to make your data more readable and accessible so you can extract useful insights without being overwhelmed by unnecessary complexity.


Every function in Google Data Studio follows a syntax, or a specific order and structure in which operators or actions should be placed. The syntax for DATETIME_TRUNC is as follows:

DATETIME_TRUNC(date_expression, part)

Here, -

represents either a Date or a Date & Time field or an expression. -
is the time part you desire to display.

This function allows you to truncate your date_expression to MICROSECOND, MILLISECOND, SECOND, MINUTE, HOUR, DAY, WEEK, ISOWEEK, MONTH, QUARTER, YEAR, or ISOYEAR, giving you substantial flexibility in handling date and time data.


Think of the DATETIME_TRUNC function as your friendly store grinder. Instead of grinding coffee beans into different coarseness levels, this function grinds dates into different levels of detail.

You select the 'part' or level you wish to view your date in, and DATETIME_TRUNC does the rest. It transforms the more precise Date & Time data into the more general form you asked for. The WEEK begins on Sunday and the ISOWEEK begins on Monday, following the ISO 8601 week boundaries.

ISOYEAR truncates the date_expression to the beginning of the ISO year, which is the Monday of the first week whose Thursday belongs to the corresponding Gregorian calendar year.

Examples of DATETIME_TRUNC Function

Let's suppose you have recorded detailed daily sales data and want to visualize them on a monthly basis for the year 2021. Here's how you can use DATETIME_TRUNC function in such a scenario for the purpose of summarizing sales:


This formula will return the 'Sales Date' truncated to the beginning of each month.

To view the data on a yearly basis:


Limitations of DATETIME_TRUNC Function

Remember, DATETIME_TRUNC function does not work for compatibility mode date types. It can only be used in conjunction with Date or Date & Time fields/expression.

Pro Tips for using DATETIME_TRUNC

To obtain maximum benefit from DATETIME_TRUNC function, carefully select the 'part' based on your business question. For instance, if you need general trends, MONTH, QUARTER or YEAR can provide the necessary insights. On the other hand, if you need to detect minute changes, opt for MICROSECOND, MILLISECOND, SECOND, MINUTE or HOUR truncations.

In conclusion, the DATETIME_TRUNC function is a versatile tool in Google Data Studio that makes data visualization easier by managing data granularity. Armed with this function, you can dive into your data ocean with a customized granularity scuba gear, surfacing with the pertinent data pearls you need.

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