When selecting your date range using the date picker, you will now have the option of selecting either "Previous period (default)" or "Same period last year" which will affect the data comparisons which are available on certain metrics.
What does Previous period refer to?
The "Previous period (default)" which we refer to will depend on the date range which you have selected on the date picker.
Example 1: If it's currently April, if you select the period "Previous Month" from the date-picker to denote March, this refers to March 1st - March 31st. In this case, the previous period will be the month of February. So, we could be comparing March data to February data:
Example 2: If however, you chose a custom date range on the date picker, and manually select March 1st - March 31st, the previous period, in this case, will be the equivalent number of days preceding the period that you have selected. So in this instance, the previous period would not be February 1st - February 28th, but instead, January 29th - February 28th (31 days):
What does Same period last year refer to?
The "Same period last year" quite literally means that we will compare the data for the date range you have selected, with data from the same date range but in the previous year.
Example: If I select the date range March 1st - April 30th 2019, and select "Same period last year", the data will be compared to March 1st - April 30th 2018:
Please note that these data comparisons don't apply to the "Total Followers" KPI, or the Follower Growth chart.