9:00?
If you're the bar owner, your personal work schedule is whatever you want it to be. However, many state and local jurisdictions set a limit to how late a bar may stay open (and sometimes even what days they can be open), so do not go outside those boundaries. As long as you are within those guidelines, do as you will.
The one here in Denver is open 24/7.
For late filers. (Taxes)
9:00 pm
its opened until midnight
most stay open till 12 but differs from store to store
Because it's hard to open at night when there are many burglars waiting to steal.
They stay up late on Christmas Eve and open them at midnight (Christmas).
until 2:60
Yes
Yes. The Answers Summit is open to late arrivals and attendees are not required to stay for every session.