Currently, when use Relative Date Filter or Slicer, when you want relative to calendar week, month or year, is possible use three operators "is in the last", "is in this" and "is in the next", which ...
v-yingjl
Community Support
Community SupportHi josef78 ,
Use Months(Calendar) as an example. Currently in power bi, if you choose Months (Calendar), then the period always consider full calendar months. which means it will start from 1st of Jan until end of Jan, because Feb in the table is not still a full calendar month.
The end date of Feb 2021 is 2021/2/14
Please refer this article which introduces it in details: Relative Date Slicer in Power BI; Simple, yet Powerful
If you want the logic is "<=" as your mentioned, perhaps you can create a new idea here and vote for it. Currently it is by designed in power bi, not a bug.
Best Regards,
Community Support Team _ Yingjie Li