### Steps to reproduce

1. Go to Administration > Calendar and dates > Date format

2. Set the `Week starts on` to Monday and Save

3. Go to My tracking page


### What is the buggy behaviour?

* Week starts on Sunday Begin of the insertion

* Behavior is the same in the calendar and the list view


End of the insertion Begin of the deletion


End of the deletion ### What is the expected behaviour?

1. Week starts on Monday


###

### Screenshots and other files

<img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/486524/content"> Begin of the deletion
End of the deletion <img class="op-uc-image op-uc-image_inline" src="/api/v3/attachments/486525/content">

### Environment information

**OpenProject version**

Core build

[200d698042949f667d391029c2521edac7809d96](https://github.com/opf/openproject/commits/200d698042949f667d391029c2521edac7809d96)

Product version

[4c0a4dabe77cbcff4c65651b74c1f02462976bab](https://github.com/opf/saas-openproject/commits/4c0a4dabe77cbcff4c65651b74c1f02462976bab)

Core version

OpenProject 16.0.0

**Browser**

* [ ] Chrome
* [x] Firefox 137.0
* [ ] Safari
* [ ] Mobile Safari
* [ ] Other (please specify)

**Operating System**

* [x] Windows 11Pro
* [ ] Mac OS X
* [ ] Mobile iOS
* [ ] Mobile Android
* [ ] Linux (please specify distro)
* [ ] Chrome OS
* [ ] Other (please specify)