#24999 [Bug]: "Month to date" view includes usage for the last day of the previous month
### Check for existing issues
- [x] I have searched the existing issues and checked that my issue is not a duplicate.
### What happened?
repro:
- go to the Usage view `/ui/?page=new_usage` - select "Month to date" as the time range
result: the usage chart shows spend for 2026-03-31 , 2026-04-01 , 2026-04-02
expected: should only show spend for 2026-04-01 , 2026-04-02
<img width="3098" height="1470" alt="Image" src="https://github.com/user-attachments/assets/4a1f78c8-95c3-42b7-96df-bf024f984b97" />
### Steps to Reproduce
noted above
### Relevant log output
```shell
```
### What part of LiteLLM is this about?
UI Dashboard
### What LiteLLM version are you on ?
v1.81.9
### Twitter / LinkedIn details
_No response_