I would like to report a problem in the date handling for both the gemini-live-2.5-flash-preview and gemini-2.5-flash-preview-native-audio-dialog models.
I’m developing a Customer Support application for a company. Customer interactions are in Italian, and perhaps the Italian language itself could be the real problem. I haven’t tested it in English. But obviously in this post I will give the examples in English.
In the system prompt, for each session, I always pass today’s date, so that the model has a time reference. The documentation containing the company information, loaded as text files, includes opening and closing times for specific periods of the year. An example could be:
- From May 1st to June 6th 2025: Open Saturdays and Sundays from 10:00 am to 7:00 pm
- From June 7th to August 31st 2025: Open daily from 9:30 am to 7:00 pm
- From September 1st to November 2nd 2025: Open Saturdays and Sundays from 12:00 pm to 7:00 pm
Let’s assume today’s date is Wednesday, August 20, 2025. In the documentation, the reference period is From June 7th to August 31st 2025.
If I ask what time does the company open on Saturday? the model responds with the timetables for the period From May 1st to June 6th 2025 or From September 1st to November 2nd 2025. And I think the reason lies in the fact that those two periods contain the word Saturday. After all, it’s an LLM, not an intelligent entity 
Now let’s assume that today’s date is Tuesday, September 2, 2025. In the documentation, the reference period is From September 1st to November 2nd 2025.
If I ask what time does the company open on Friday? the model responds with the timetables for the period From June 7th to August 31st 2025. I think the reason is that during that period it is open every day, while in what would be the correct period From September 1st to November 2nd 2025 it is only open on Saturdays and Sundays.
Another funny example is the following response provided by the model when asked a question about the period, rather than the day of the week: During this period, the company is only open on Saturdays and Sundays from 12:00 pm to 7:00 pm. Would you also like to know the opening hours for the weekend?. Oh, my goodness!
In the system prompt I’ve included instructions to calculate which day of the month corresponds to which day of the week a customer can request. The calculation is based on today’s date, which I pass to the system prompt. And I’ve verified by asking the model direct questions, and it’s always made the right calculation and gave the right answer. So the model knows what date the customer question refers to.
I also tried creating a function that returns the date for a specific day of the week. However, the problems mentioned above remain. The model knows the correct date, but then refers to the wrong period.
Unfortunately, as noted in many other posts on this forum, the gemini-2.5-flash-preview-native-audio-dialog model almost never calls functions. So this function trick only applies to the gemini-live-2.5-flash-preview model. But since I need to test both models, maintaining a single code base for now, I prefer the solution with the date calculation instructions in the system prompt.
Therefore, I believe even more that the problem lies in the interpretation of human language when it comes to dates, at least in the Italian language.
After 5 days of trying and cursing I managed to find a solution. I added the days of the week the company is closed for the periods when it’s only open on Saturdays and Sundays. For example:
- From May 1st to June 6th, 2025: Closed Mondays, Tuesdays, Wednesdays, Thursdays, and Fridays - Open Saturdays and Sundays from 10:00 AM to 7:00 PM
- From June 7th to August 31st, 2025: Open daily from 9:30 AM to 7:00 PM
- From September 1st to November 2nd, 2025: Closed Mondays, Tuesdays, Wednesdays, Thursdays, and Fridays - Open Saturdays and Sundays from 12:00 PM to 7:00 PM
However, this involves more documentation edits, more work for me and a waste of tokens.
It would be very helpful if you could train the models to better understand date concepts and to independently calculate which date a given day of the week falls on, given a reference date.
In any case, thank you for your valuable work.