Bug: gpt-realtime usually miscomputes “next weekday” by +1 day (appears to use 2025 calendar)

[victorm750]

We’re repeatedly observing incorrect date resolution with gpt-realtime when the user provides a weekday (e.g., “Tuesday”). The model usually resolves the date one day late.

Example from today (Saturday, 14th Feb; call_id: call_xet5Qv9i0abY6sjn):

Me : “Hey, I would like to do a reservation, please.”

AI: “Sure! For what date would you like to make the reservation?”

Me: “Tuesday.”

...

And model got:

"arguments" => "{ \n \"date\": \"2026-02-18\", ...}

Incorrect, since Tuesday is 2026-02-17.

We even added explicit context and examples in our prompt to guide relative-date calculation. It’s dynamic, but see below how it reads today:

# Context

- Current date (today): 2026-02-14 (Saturday) - when gathering desired date, take this as reference for any relative date and next-occurrence weekday the user mentions (e.g. “tomorrow” is 1 day from now, so it means ‘2026-02-15’; “Tuesday“ is 3 days from now, so it means ‘2026-02-17’).

But it still fails (even when the weekday mentioned is the example itself!)

We’ve encountered this multiple times (e.g., “Friday 14th” when Friday should have been the 13th in the given context, etc.). So this seems like a systematic weekday/date mapping error rather than a one-off hallucination.

Interestingly, the resolved MM-DD always matches the 2025 weekday.

To further experiment, we asked “which date is next Tuesday?” to a raw gpt-realtime model in the Playground (default system message only: “You are a helpful assistant”), and it also returned an incorrect date. See screenshot (this is from today, Saturday 14th Feb as well):

This is critical for booking/scheduling use cases because it makes the assistant unreliable.

@OpenAI_Support @Sean-Der , is this a known issue in gpt-realtime? Is there any recommended mitigation?

Thank you in advance

[_j]

You were trained up to a knowledge cutoff of 2026-02. What day of the week is 2027-08-31?

This could help, and could help your AI when this critical for booking and scheduling:

Why does GPT-4.1 get weekdays wrong in long date tasks?

Quick brainstorm of what you can furnish the AI automatically or as a tool to call. """ai_cal.py - produce markdown calendars for AI consumption""" from __future__ import annotations import calendar import datetime def markdown_calendar(year: int, month: int, month_count: int = 1) -> str: def coerce_int(name: str, value: object) -> tuple[int | None, str | None]: if type(value) is bool: return None, f"Error: {name} must be an integer, got bool ({value})." if is…

Something I recently learned is that markdown tables don’t need outer pipes, and that since numbers are unjoinable tokens, you can save more input by removing all the whitespace padding around number columns (while keeping it for words, which benefit from a leading space.)

[victorm750]

@_j very much appreciated we added the markdown calendar in the instructions as per your suggestion, and it’s getting relative dates properly now. Thank you!