microsoft/qlib · error · IndexError

`start_time` uses a future date, if you want to get future t

Error message

`start_time` uses a future date, if you want to get future trading days, you can use: `future=True`

What it means

Error "`start_time` uses a future date, if you want to get future trading days, you can use: `future=True`" thrown in microsoft/qlib.

Source

Thrown at qlib/data/data.py:145

        Returns
        -------
        pd.Timestamp
            the real start time.
        pd.Timestamp
            the real end time.
        int
            the index of start time.
        int
            the index of end time.
        """
        start_time = pd.Timestamp(start_time)
        end_time = pd.Timestamp(end_time)
        calendar, calendar_index = self._get_calendar(freq=freq, future=future)
        if start_time not in calendar_index:
            try:
                start_time = calendar[bisect.bisect_left(calendar, start_time)]
            except IndexError as index_e:
                raise IndexError(
                    "`start_time` uses a future date, if you want to get future trading days, you can use: `future=True`"
                ) from index_e
        start_index = calendar_index[start_time]
        if end_time not in calendar_index:
            end_time = calendar[bisect.bisect_right(calendar, end_time) - 1]
        end_index = calendar_index[end_time]
        return start_time, end_time, start_index, end_index

    def _get_calendar(self, freq, future):
        """Load calendar using memcache.

        Parameters
        ----------
        freq : str
            frequency of read calendar file.
        future : bool
            whether including future trading day.

View on GitHub (pinned to 79633dd950)

Solutions

1. Pass `future=True` if you intentionally want future trading days.
2. Use a `start_time` that is not in the future relative to the calendar.

When it happens

Trigger: This error is raised at qlib/data/data.py:145 when the guard condition fails: "`start_time` uses a future date". It triggers when the code path receives input or a state that violates the precondition checked at this point — e.g. an unimplemented abstract method being called, an unsupported argument type/value, or an invalid configuration. To avoid it, satisfy the documented precondition before this call: implement the required method in your subclass, or pass a supported value of the expected type as described by the message.

Common situations: See trigger scenarios.

AI-assisted analysis of microsoft/qlib@79633dd950 (2026-08-15). Data as JSON: /api/errors/1c4ac98f31cb7a64. Report an issue: GitHub.