Offset of days when displaying Day View from Month View

[sphh]

Checklist

• I can reproduce the bug with the latest version given here.
• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the bug report will be dismissed otherwise.
• This issue contains only one bug.
• I have read and understood the contribution guidelines.

Affected app version

Version 1.0.3

Affected Android/Custom ROM version

Android 8.1

Affected device model

Unihertz Jelly Pro

How did you install the app?

F-Droid / IzzyOnDroid

Steps to reproduce the bug

1. Open the Fossify Calendar app.
2. Open the Monthly View.
3. Tap on a date in the first week displayed (the first row) --> the Day View opens showing the correct (the tapped) day.
4. Tap on a date in the second week displayed (the second row) --> the Day View opens showing the day after the tapped day (day+1).
5. Tap on a date in the third week displayed (the third row) --> the Day View opens showing two days after the tapped day (day+2).
6. And so on.

Expected behavior

The correct day should open in the Day View (without any offset).

Actual behavior

The day, which is shown in the Day View is always offset by the number of rows the day is in in the Month View (the number of row is 0-based).

Screenshots/Screen recordings

No response

Additional information

This also happens with the Monthly and Daily View.

[sphh]

I just noticed, that the behaviour described above can only be observed, if the display of the week numbers is switched on.