[Bug] Year does not affect the progress in day-custom

[Sandr-aa]

The year does not seem to affect the progress, for example, with this code

```progressbar
kind: day-custom
name: Schuljahr
min: 2024-08-05
max: 2024-08-28
```
```progressbar
kind: day-custom
name: Schuljahr
min: 2024-08-05
max: 2025-08-28
```

both progress bars show the same progression although the second time span is an year longer

[AndreCaseyScott]

+1, Can confirm.

I was confused when only changing the year.

id: test2
kind: day-custom
min: 2024-01-08
max: 2029-01-08