I have never had trouble with any actor being able to visualise things. They are amazing. As long as you have your monster head on a long stick so you can hold it up there and you can wave it around and let them see it and explain it to them they are just great.
Time has no divisions to mark its passage there is never a thunder-storm or blare of trumpets to announce the beginning of a new month or year. Even when a new century begins it is only we mortals who ring bells and fire off pistols.