In Polar Analytics, you can use our date filters to easily compare your data to either the previous period or the previous year. If you opt to compare data to the previous year, Polar will automatically compare the data to the same exact calendar dates from the year prior (for example, in the screenshot below, the current date range is Wednesday, September 28th, 2022 - Thursday, October 27th, 2022, compared to Tuesday, September 28th, 2022 - Wednesday, October 27th, 2022).

There may be some cases where you'd like to compare the data to a different day from the previous year (for example, if you'd like to compare to the last Wednesday of September from last year, rather than the 28th of September). To achieve this, you can manually select the day that you'd like to compare to within the date range interface under "Compare to".