This article explains how Oura uses different 24-hour segments to define the Sleep Day, Calendar Day, and Activity Day.

 

Oura divides time in different ways for different purposes. There are 3 main types of days within the Oura experience:

• Activity Day: from 4 am to 4 am
• Calendar Day: from 12 am to 12 am
• Sleep Day: from 6 pm to 6 pm

 

 

Activity Day

The Activity Day is the 24-hour period within which you gather activity towards your Activity Goal. It’s like a bucket: It gathers all the activity between 4 am and 4 am and stamps it with the date of the first day.

• Example: You go dancing on New Year’s Eve and dance the night away until 3 am. All this activity will be counted for the day of 31/12/20XX.
  
  

Sleep Day

The Sleep Day is the 24-hour period within which the longest continuous sleep will give you a Sleep Score for that Calendar Day. It runs from 6 pm to 6 pm.

• Example: You wake up on New Year’s Day at 10 am after going to bed at 4 am. You check the app and get a Sleep Score for 6 hours of sleep.
  
  

Calendar Day

The Calendar Day is the 24-hour period between midnight and midnight, according to the timezone set by the user's mobile device.