14.5. DATETIME_ADD() in Looker Studio

In this lesson, we'll explore using the DATETIME_ADD() function in Looker Studio to calculate new dates by adding or subtracting a set amount of time with a specified interval. For instance, you may want to determine the next billing date for subscription services based on when someone became a paid member.

Calculating First Re-bill Date

To calculate the first rebill date, utilize the DATETIME_ADD() function as follows:

DATETIME_ADD(date, INTERVAL num granularity)

The parameters you'll need to input are:

date: The initial date (in our example, when the user became a paid member)
num: The number of units of the specified granularity (e.g., 4 weeks)
granularity: The desired granularity of the interval (e.g., week, day)

In our example, we could calculate the first rebill date that occurs four weeks after the initial date:

DATETIME_ADD(paid_member_date, INTERVAL 4 week)

Calculating the Next Billing Date

Calculating the next billing date involves a more dynamic and flexible approach. While we can determine the current date, we need to determine how many months to add to the initial paid date. We can use the DATETIME_DIFF() function to find the difference between the current date and the initial paid member date. You'll need to use this information and additional calculations to determine the next billing date.

Implementing these methods allows you to handle recurring billing and payment schedules more accurately by exclusively considering each user's membership history. Remember that using Looker Studio functions like DATETIME_ADD(), DATETIME_DIFF(), and CURRENT_DATE() can offer additional layers of flexibility and precision for your data analysis, benefiting your business operations and decision-making processes.