BerriAI/litellm · error · HTTPException

start_date must be on or before end_date

Error message

start_date must be on or before end_date

What it means

Range sanity check for tag listing: after parsing both dates, start_date greater than end_date is rejected with 400 because an inverted range can never match data. At-fault input is an out-of-order date pair.

Source

Thrown at litellm/proxy/management_endpoints/tag_management_endpoints.py:568

def _validate_tag_list_date_range(start_date: str | None, end_date: str | None) -> None:
    """Require both dates together, and enforce YYYY-MM-DD format with start <= end."""
    if (start_date is None) != (end_date is None):
        raise HTTPException(
            status_code=400,
            detail="start_date and end_date must be provided together",
        )
    if start_date is None:
        return
    try:
        start: Final = datetime.strptime(start_date, "%Y-%m-%d")
        end: Final = datetime.strptime(end_date, "%Y-%m-%d")
    except ValueError as e:
        raise HTTPException(
            status_code=400,
            detail=f"Invalid date format, expected YYYY-MM-DD: {e}",
        )
    if start > end:
        raise HTTPException(
            status_code=400,
            detail="start_date must be on or before end_date",
        )


@router.get(
    "/tag/list",
    tags=["tag management"],
    dependencies=[Depends(user_api_key_auth)],
)
async def list_tags(
    user_api_key_dict: UserAPIKeyAuth = Depends(user_api_key_auth),
    start_date: str | None = Query(
        None,
        description=(
            "Optional start date (YYYY-MM-DD). When provided together with "
            "end_date, dynamic tags are limited to those active in the window. "
            "Stored tags are always returned."

View on GitHub (pinned to 77b7c6c40c)

Solutions

1. Set start_date on or before end_date.

When it happens

Trigger: Thrown at litellm/proxy/management_endpoints/tag_management_endpoints.py:568 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of BerriAI/litellm@77b7c6c40c (2026-08-18). Data as JSON: /api/errors/412b74478feda3bb. Report an issue: GitHub.