If you are working to D1.1 than that is what you must obey. You need to have a copy of the code in order to do that.
There are a variety of factors that dictate how long an electrode can be exposed, if it may be rebaked at all, how many times it may be rebaked, at what temperature etc. The only way to get an absolute ruling is to see how your situation works with what ever code you are attempting to comply with.
If you are asking in general terms why not just go direct to the manufacturer of your Excalibur 7018 and see what they say about their own product
http://www.lincolnelectric.com/knowledge/articles/content/storing.asp