Slider on Qlik Sense

[Amal]

Hello,

I had a Qlikview application and I want to do a better version of it on Qlik Sense. Although, in QV I had a slider that allowed me to select an interval of dates and I want to do it in QS.

I saw that you can do a "distribution graph" which is fine for me (link : https://community.qlik.com/t5/New-to-Qlik-Sense/Range-Slider-filter-in-QlikSense/td-p/1587930), cause I don't want an extension. However, I have a lot of dates (see attached : QS_distribution.png). 

The solution I thought about would be to create smaller range of dates : i want to have the date every 6 months. For exemple if the min date is 06/2020, I want to have in the distribution diagram : 06/2020, 12/2020, 06/2021, 12/2021. 

My question would be : how to add a field in my calendar that would tell me, which interval my date belongs to ? How to create those intervals ? 

If I am not clear, please ask questions. Thanks.