How can I determine what time a request was created?

[David Seeto]

We're looking to implement Jira Service Management: one of current SLAs is "by the end of the next business day", which means it's not a fixed number of business hours from when the request is created but however many it is from the time that the request is created until the end of the next business day

This has been asked before in https://community.atlassian.com/t5/Jira-Service-Management/Can-I-set-SLA-goal-for-end-of-next-business-day/qaq-p/306896, in which the answer currently is "See if there's an app".

It occurs to me that if you've got fixed business hours like we have, we could actually do this by configuring multiple SLAs depdending on when the request is created - so if we have 10 business hours between 8 am and 6 pm, then requests created between 8 am and 9 pm could have an SLA of 20 business hours; requests created between 9 am and 10 am have an SLA of 19h, requests created between 10 am and 11 am have an SLA of 18h etc etc etc. That seems like a lot of work, but it would be possible.

To do that, I need to be able to figure out what time the request was created in JQL: there are functions that indicate that the Created field definitely has the time in it, because you can use functions like startOfDay() and endOfDay(), but I didn't see how I could extract this info.

Any suggestions?