Dates and times

You can use Looker Studio to visualize and compare dates and times in charts and graphs, and let users adjust the report's date range. You can also use date functions in calculated fields to manipulate and transform date and time data.

In this article:

• Date and time data types
• Date & Time (compatibility mode)
• Upgrade a compatibility mode date field
• Use dates and times in charts
• Change the data type in a chart vs. the data source
• Use dates and times in calculated fields
• Related resources

Date and time data types

Looker Studio supports the following calendar date and time data types:

Type	Example data
Date	Sep 15, 2020
Date & Time	Sep 15, 2020, 6:10:59:59 PM
Year	2020
Year Quarter	Q3 2020
Year Month	Sep 2020
ISO Year Week	Sep 14, 2020 to Sep 20, 2020 (Week 38)
Date Hour	Sep 15, 2020, 6 PM
Date Hour Minute	Sep 15, 2020, 6:10 PM
Quarter	Q3
Month	September
ISO Week	Week 35
Month Day	Sep 15
Day of Week	Tuesday
Day of Month	23
Hour	6 PM
Minute	52

You can change a field's data type from the field's Type menu in the data source:

You can also change a field's data type by editing the field in the SETUP tab of a report:

Date & Time (compatibility mode)

Date and time dimensions in data sources created before September 15, 2020 use a Date & Time (compatibility mode) data type. Compatibility mode dates include the format or an example in the name, as shown below:

Compatibility mode dates have both a Format Type and a Granularity option when editing the field in charts. To adjust a chart's date grouping, use the Granularity option.

Upgrade a compatibility mode date field

Compatibility mode dates continue to work in your existing components and calculated fields. However, you can't use compatibility mode dates with all of the available date and time functions. To use those functions, you can upgrade your date fields to new Date or Date & Time data types.

When you upgrade a compatibility mode date to a new Date or Date & Time type:

• You can use the upgraded field with functions such as DATETIME_ADD, DATETIME_DIFF, EXTRACT, and more.
• Calculated fields and filters that expect a specific data format might fail, due to the new data type's formatting. You can fix any broken components by adjusting the formulas or filters to use the upgraded field's new format.
• You can't change a Date or Date & Time field to compatibility mode. The compatibility mode type is turned off for upgraded fields.
• If you decide you want to undo the change, use version history in the data source to restore an earlier version.

To upgrade:

1. Sign into Looker Studio.
2. Edit your data source.
3. Locate the compatibility mode date field you want to convert.
4. Click the field's Type menu, then select Date & Time.
5. Select the desired date type.
6. In the dialog box that appears, click UPGRADE.

Because upgrading might impact your reports, you must upgrade date and time fields individually. Reconnecting your data source won't upgrade the fields.

The following connectors don't support the new Date and Date & Time data types, so you can't upgrade to or create those types in data sources using these connectors:

• Cloud Spanner
• YouTube Analytics
• BigQuery using Legacy SQL

Use dates and times in charts

You can group (aggregate) the data in your charts by different levels of date granularity according to the date field's data type. For example, adding a Date field to your chart groups the data by year, month, and day. To group the data by month, change type to Month, or use a Month field from your data source.

1. Chart showing Metric by full date.
2. Chart showing Metric by month.

Change the data type in a chart vs. the data source

Changing a field's data type in the data source changes that field everywhere it's used. This may also limit how you can use that field in charts.

Best practice

Always have a full Date or Date & Time field in your data source. Use that field in your charts and adjust the field's type in the chart:

1. Edit your report.
2. Select the chart.
3. Hover over the date field, then click Edit.
4. Select the new field type.

You can’t change the type within the chart when the field type in the data source is only a date part (for example, Month or Day of Week).

Use dates and times in calculated fields

You can use functions in calculated fields to create new columns of date and time data in your data source or directly in components on the report.

For example, you can construct a complete date from separate numeric day, month, and year fields using the DATE function. You can extract date and time parts from a date with functions like YEAR, DAY, and HOUR. You can calculate the difference between 2 dates using DATETIME_DIFF, or add a certain number of time parts using DATETIME_ADD.

Learn more about date and time functions.

Date and Date & Time literals

To use literal date and time values in a calculated field, you can precede the value with the appropriate marker:

Literal	Canonical data format
DATE	'YYYY-[M]M-[D]D'
DATETIME	'YYYY-[M]M-[D]D [[H]H:[M]M:[S]S]'

Examples:

Calculate the difference between a date from data and a specific fixed date:

DATETIME_DIFF(date_field, DATE "2008-12-25", DAY)	

Format a date as text:

FORMAT_DATETIME("%x", DATE "2008-12-25")

Related resources

• Set the report date range
• Let your viewers control the date range
• Calculated fields
• Looker Studio function list