Hello, I am currently developing an AI calendar which is a widget based on ChatGPT.
My problem is simple. When I ask for the date on chatgpt directly it gives me today’s date without any problem. When I make an API call, it is unable to give me today’s date.
My question is simple. Why and how can I solve that ??
Thanks in advance. Looking forward to reading you.
Welcome to the forum.
You could likely use a Function call that would query the date/time on your system then return it in natural language.
You have to supply the date and other relevant information yourself before the AI can make use of it. I recommend putting the date in the system prompt.
AI Like Chat GPT is made out of Data. It is like a machine studying the data, once that machine studied the data, it will go to the market as a model.
This is why GPT does not know the date. Because it is based on data he has previously seen
There’s no need for a “function call” for a date - although dealing with dates you will find it beneficial to add some functions that can compute or display calendars, because the AI won’t do a good job of querying for a question of “got any available appointments next tuesday?”.
Instead, I’d recommend two system prompt dates to keep the AI straight, because a system prompt that appears earlier than later chat exchanges can also serve to confuse the understanding of what’s going on if you provide the precision of time: “Conversation session start time” AND “current time”.
Note I said you “could” not you “should”… 
Concur with the other answers that just inserting it into prompt from your system is better and it should be able to recall it when requested. Does use a bit more tokens, but the cost is dropping all the time.
This is the method I used and it works perfectly. Thanks for your help
Of course, my question is how OpenAI solves this problem on native ChatGPT but not on their API. And how I can fix that
Exact, works perfectly, thanks for your help 
Ohh, now I understand. If you are using the api in a programming setup, you can just send the current date using the libraries from the programming language. If I may help, please tell me what you are using!
I can get the Unix Epoch time, when I request it.
Also you can fetch the timezone (it’s Zulu time, or default to zero / 0).
See request : Unix Epoch Date Request
Knowing this, you can use it as a “default” and do the math for your API yourself.
I am working with the assistant api. And had the best results with a function call that the assistant can use to request the time. Because assistants don’t have system prompt to my knowledge, and I still am debating your approach using prompts with session and current time. I was wondering if you have any success with such an approach for assistants?
Yes, as noted, in ChatGPT we have a system that takes todays date and adds it to the system prompt. You can do the same!