Make new calendar visible on a certain date

[Jessie Faust]

We have 2 calendars in our Space and end users have accidentally muddled the entries over a long period of time. Calendar 1 was for people to document personal vacations, working off-site, etc. Calendar 2 was for department events, visitors, department meetings, etc.  Now we have vacations on the department calendar and vice versa for dept events.

My manager wants a new calendar to just log ALL events.  
I cannot find an answer to:

• Can I make a new Calendar but keep end users from seeing it until January 1st?  
• Can I import events from the 2 existing calendars to the New Calendar? 
  (because we want to delete the previous calendars)

Or I'm open to any variety of best practice in this area.

Thanks much!
Jessie