今天是几号用英语怎么说

"What's the date today in English?"

If you are asking this question in a more formal context, you can say "Good morning/afternoon/evening, what's the date today?" or "may I ask you what the date is today?". If you are asking someone directly, you can say "Hey, do you know what the date is today?".

However, if you want to ask about the date in a more concise way, you can simply say "What's today's date?". This is a very common way to ask for information about the date in English.