Statistics: Date selection is wrong

[flecken66]

Describe the bug The date selection on the statistics page uses an incorrect interval. An open interval is used, but a closed interval should be used. (https://en.m.wikipedia.org/wiki/Interval_(mathematics)#Definitions)

That means when I select a timeperiod I only get the statistics between the start and end date but not from the start and end date. This is not very intuitive and creates the edge case when start and end date are identical you never get any stats.

Screenshots

Smartphone:  - Device: Pixel 7  - OS: Android 13  - Version: v2.1.4-play (126)