The answer to this is that it is possible, but you will have to re-write (and then maintain) the whole of Jira and all the add-ons you want to use with it.
So, Mikael is right - you can create a custom field with your date/time and number with a bit of code.
But I'd like to point out that it's mostly useless. Your users will quickly start talking in Jira keys because they offer a simple unique identifier that gives them immediate information, instead of having to think about when something was created. (This seems like an incredibly poor choice of identifier for issues, part of me is curious about how you'd come to think you want such a poor scheme?)
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