How do you say how was your day today in Hindi?

There are a few ways to say "How was your day today?" in Hindi, depending on the level of formality and closeness you have with the person:

Formal:

* आज आपका दिन कैसा रहा? (Aaj aapka din kaisa raha?) - This is the most formal way to ask.

* आज आपका दिन कैसे बीता? (Aaj aapka din kaise bita?) - This is also a formal way to ask, but slightly less formal than the first option.

Informal:

* आज आपका दिन कैसा था? (Aaj aapka din kaisa tha?) - This is a more casual way to ask.

* आज कैसा रहा आपका दिन? (Aaj kaisa raha aapka din?) - This is another casual way to ask.

* आज का दिन कैसा रहा? (Aaj ka din kaisa raha?) - This is the most casual way to ask, and can be used with close friends or family.

You can also say:

* आपका दिन कैसा रहा? (Aapka din kaisa raha?) - This is a more general way to ask, and can be used in both formal and informal situations.

Remember that the best way to say something in Hindi will depend on the context and your relationship with the person you are talking to.