By now you would have heard us mention the 28-day rolling time-window we use to calculate a number of your health ratings. If you’re unsure what we mean by this, then don’t sweat it - you’re part of the majority! Let’s shed some light on this with an example. If today’s date was July 29, we’ll analyse your device data from the previous 28 days – July 1 to July 28. Hence, a time-window of 28 days. Make sense?

When the next day begins, the time-window rolls forward one day. This is why it’s called a rolling time-window. The data recorded on July 1 has now expired and yesterday’s data from July 29 is included instead. 

Does this mean you need to wear your device everyday? While this is ideal to ensure the most reliable and accurate ratings, it’s also A-OK to take a breather from it every now and then. To be eligible for the following SimplyMe health ratings you need to provide us with a minimum of 1 day/nights of device data within the 28-day rolling window:


  • Resting Heart Rate rating
  • VO2 Max rating


  • Time Asleep rating
  • Sleep Efficiency rating


  • Daily Step Average rating

Please note: Your Mind rating uses a 14-day rolling time-window.